Directional differential pressure detector having an inclined conduit and a pitch indicator

ABSTRACT

An apparatus indicates the presence of a threshold directional differential pressure between separated adjacent spaces. A conduit contains a movable element that indicates whether the pressure difference between the two spaces is at least as high as a threshold pressure difference. The apparatus is adjustable to have different threshold set points by adjusting the conduit inclination. The conduit may be rotatable about an axis of rotation which is transverse to a barrier, and the conduit may be rotatable along a plane. The apparatus may include a pitch level configured to indicate whether the apparatus is oriented correctly with respect to pitch.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation and claims the benefit of U.S.application Ser. No. 15/821,440, filed Nov. 22, 2017, which claims thebenefit under 35 U.S.C. § 119(e) of U.S. Provisional No. 62/426,172,filed Nov. 23, 2016, each of which is hereby incorporated by referencein its entirety.

FIELD

Aspects of the present disclosure relate generally to methods andapparatuses for detecting the presence of a directional differentialpressure.

DISCUSSION OF RELATED ART

Various applications within hospitals, laboratories, pharmaceuticalfacilities, clean room facilities, etc., often require a particulardirection of air flow to be maintained, such as between neighboringrooms, compartments, corridors, ducts, or other spaces. The pressure ofa room relative to adjacent space(s) will determine the net direction ofair flow through an opening into or out of the room.

For example, a hospital operating room may be kept under a positivepressure so that air flows out of the room, thereby preventingunfiltered or contaminated air from entering the room from adjacentspaces. This positive pressure is accomplished by supplying clean air tothe operating room at a greater flow rate than the flow rate at whichair is exhausted from the room by the room's ventilation system.

Or, if a hospital patient is infected with an airborne communicablepathogen, a patient isolation room may be kept under a negative pressurewhich is accomplished when the rate at which potentially contaminatedair is exhausted from the room is greater than the rate at which air issupplied to the room from the room's ventilation system. Such a negativepressure arrangement, where the room is under a comparatively lowerpressure than its immediate surroundings, prevents potentiallycontaminated air from exiting the room and escaping into surroundingspace(s).

The net differential pressure between rooms will cause air to flowthrough an opening from one room to the other in the direction from ahigher pressure to a lower pressure. The desired degree of differentialpressure to be maintained between rooms, compartments, corridors, etc.will vary, depending on the application.

Accordingly, it is often desirable to closely monitor the generaldirection of potential or actual air flow between compartments as wellas the particular magnitude of differential pressure causing the net airflow.

SUMMARY

According to one embodiment a device for indicating a presence of adirectional differential pressure between a first space and a secondspace separated from the first space by a barrier is provided. Thedevice permits fluidic pressure connection between second space and apivot arm in the first space. The device includes a first conduitarranged to extend through at least a portion of the barrier separatingthe first space and the second space. The device further includes arotating base which is rotatable relative to the first conduit. A pivotarm is arranged to form a fluidic pressure connection with the firstconduit. The pivot arm is rotatably attached to the rotating base topermit adjustment of an inclination of the pivot arm relative to ahorizontal plane among a plurality of inclination angles in which afirst, vertically lower region of the pivot arm is vertically lower thana second, vertically higher region of the pivot arm. The device alsoincludes at least one movable element disposed within the pivot arm andmovable from the first, vertically lower region of the pivot arm to thesecond, vertically higher region of the pivot arm in response to adirectional differential pressure between the first and second spaces.

According to one embodiment, a device for indicating directionaldifferential pressure between two spaces is disclosed. The devicepermits fluidic pressure connection of a first space and a second spaceseparated by a barrier. The device includes a first conduit arranged toextend through at least a portion of the barrier separating the firstspace and the second space. Also included is a pivot arm fluidicallyconnected to the first conduit and arranged to pivot relative to thefirst conduit to adjust an inclination of the pivot arm within avertical plane and relative to a horizontal plane among a plurality ofinclination angles in which a first, vertically lower region of thepivot arm is vertically lower than a second, vertically higher region ofthe pivot arm, wherein the first conduit and the pivot arm form apassageway for fluid. A transition region is present where thepassageway is first surrounded by the pivot arm when traveling in adirection toward the pivot arm, wherein the pivot arm is arranged suchthat pivoting the pivot arm within the vertical plane does not change alocation of the transition region relative to the first conduit. Thedevice also includes at least one movable element disposed within thepivot arm and movable from the first, vertically lower region of thepivot arm to the second, vertically higher region of the pivot arm inresponse to a directional differential pressure between the first andsecond spaces.

According to another embodiment, a device for indicating directionaldifferential pressure between two spaces is disclosed. The devicepermits fluidic pressure connection of a first space and a second spaceseparated by a barrier. The device includes a first conduit arranged toextend through at least a portion of the barrier separating the firstspace and the second space. Also included is a pivot arm fluidicallyconnected to the first conduit and arranged to pivot relative to thefirst conduit about a pivot axis, wherein pivoting the pivot arm aboutthe pivot axis adjusts an inclination of the pivot arm relative to ahorizontal plane among a plurality of inclination angles in which afirst, vertically lower region of the pivot arm is vertically lower thana second, vertically higher region of the pivot arm, and whereinpivoting the pivot arm about the pivot axis does not change a directionof the pivot axis, wherein the first conduit and the pivot arm form apassageway for fluid. A transition region exists where the passageway isfirst surrounded by the pivot arm when traveling in a direction towardthe pivot arm, wherein the pivot arm is arranged such that pivoting thepivot arm within the vertical plane does not change a location of thetransition region relative to the first conduit. The device alsoincludes at least one movable element disposed within the pivot arm andmovable from the first, vertically lower region of the pivot arm to thesecond, vertically higher region of the pivot arm in response to adirectional differential pressure between the first and second spaces.

According to a further embodiment, a device for indicating directionaldifferential pressure between two spaces is disclosed. The devicepermits fluidic pressure connection of a first space and a second spaceseparated by a barrier. The device includes a first conduit arranged toextend through at least a portion of the barrier separating the firstspace and the second space. Also included is a pivot arm fluidicallyconnected to the first conduit and arranged to pivot relative to thefirst conduit to adjust an inclination of the pivot arm within avertical plane and relative to a horizontal plane among a plurality ofinclination angles in which a first, vertically lower region of thepivot arm is vertically lower than a second, vertically higher region ofthe pivot arm. The device forms a fluid flow passageway from the firstconduit to an entrance of the pivot arm, and the pivot arm is arrangedsuch that pivoting the pivot arm does not change a path of the fluidflow passageway from the first conduit to the pivot arm entrance. Thedevice includes at least one movable element disposed within the pivotarm and movable from the first, vertically lower region of the pivot armto the second, vertically higher region of the pivot arm in response toa directional differential pressure between the first and second spaces.

According to yet another embodiment, a device for indicating directionaldifferential pressure between two spaces is disclosed. The devicepermits fluidic pressure connection of a first space and a second spaceseparated by a barrier. The device includes a first conduit arranged toextend through at least a portion of the barrier separating the firstspace and the second space. Also included is a pivot arm fluidicallyconnected to the first conduit and arranged to pivot relative to thefirst conduit to adjust an inclination of the pivot arm within avertical plane and relative to a horizontal plane among a plurality ofinclination angles in which a first, vertically lower region of thepivot arm is vertically lower than a second, vertically higher region ofthe pivot arm, wherein the pivot arm is pivotable to an inclinationangle of at least 10° relative to the horizontal plane. The deviceincludes at least one movable element disposed within the pivot arm andmovable from the first, vertically lower region of the pivot arm to thesecond, vertically higher region of the pivot arm in response to adirectional differential pressure between the first and second spaces.

According to another embodiment, a device for indicating directionaldifferential pressure between two spaces is disclosed. The devicepermits fluidic pressure connection of a first space and a second spaceseparated by a barrier. The device includes a first conduit arranged toextend through at least a portion of the barrier separating the firstspace and the second space. Also included is a pivot arm fluidicallyconnected to the first conduit and arranged to pivot relative to thefirst conduit to adjust an inclination of the pivot arm within avertical plane and relative to a horizontal plane among a plurality ofinclination angles in which a first, vertically lower region of thepivot arm is vertically lower than a second, vertically higher region ofthe pivot arm. A level is positioned to indicate whether an axis ofrotation of the pivot arm is horizontal. A directional differential setpoint indicator is configured to indicate a threshold directionaldifferential pressure between first and second spaces that is sufficientto cause the at least one movable element to move from the first,vertically lower region of the pivot arm to the second, verticallyhigher region of the pivot arm, based on the angle of inclination of thepivot arm. The device also includes at least one movable elementdisposed within the pivot arm and movable from the first, verticallylower region of the pivot arm to the second, vertically higher region ofthe pivot arm in response to a directional differential pressure betweenthe first and second spaces.

According to a further embodiment, a device for indicating directionaldifferential pressure between two spaces is provided. The device permitsfluidic pressure connection of a first space and a second spaceseparated by a barrier. The device includes a first conduit arranged toextend through at least a portion of the barrier separating the firstspace and the second space. Also included is a pivot arm fluidicallyconnected to the first conduit and arranged to pivot relative to thefirst conduit to adjust an inclination of the pivot arm within avertical plane and relative to a horizontal plane among a plurality ofinclination angles in which a first, vertically lower region of thepivot arm is vertically lower than a second, vertically higher region ofthe pivot arm. A level is positioned to indicate whether an axis ofrotation of the pivot arm is horizontal. A differential set pointindicator is configured to indicate a threshold differential pressurebetween first and second spaces that is sufficient to cause the at leastone movable element to move from the first, vertically lower region ofthe pivot arm to the second, vertically higher region of the pivot arm,based on the angle of inclination of the pivot arm. At least one movableelement is disposed within the pivot arm and movable from the first,vertically lower region of the pivot arm to the second, verticallyhigher region of the pivot arm in response to a directional differentialpressure between the first and second spaces.

Advantages, novel features, and objects of the present disclosure willbecome apparent from the following detailed description of the presentdisclosure when considered in conjunction with the accompanyingdrawings, which are schematic and which are not intended to be drawn toscale. For purposes of clarity, not every component is labeled in everyfigure, nor is every component of each embodiment of the presentdisclosure shown where illustration is not necessary to allow those ofordinary skill in the art to understand the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are not intended to be drawn to scale. In thedrawings, each identical or nearly identical component that isillustrated in various figures is represented by a like numeral. Variousembodiments of the present disclosure will now be described, by way ofexample, with reference to the accompanying drawings. The embodimentsand drawings shown are not intended to narrowly define the presentdisclosure.

FIG. 1 is a cross-sectional view of a device subject to a differentialpressure in accordance with some embodiments;

FIG. 2 is a cross-sectional view of the device of FIG. 1 at a differentorientation;

FIG. 3 is a perspective view of another device for detecting adirectional differential pressure in accordance with some embodiments;

FIG. 4 is a cross-sectional view of the device of FIG. 3;

FIG. 5 is an exploded perspective view of a portion of the device ofFIG. 3;

FIGS. 6 and 7 are cross-sectional views of a portion of the device ofFIG. 3 for detecting a directional differential pressure in accordancewith some embodiments;

FIG. 8 is a cross-sectional view of a device for detecting a directionaldifferential pressure in accordance with some embodiments;

FIG. 9 is a partial perspective view of the device of FIG. 8;

FIG. 10 is a partial cross-sectional view of another device fordetecting a directional differential pressure in accordance with someembodiments;

FIG. 11 is a top schematic view of one embodiment of a device fordetecting a directional differential pressure in accordance with someembodiments;

FIG. 12 is an exploded perspective view of the embodiment of FIG. 11;

FIG. 13 is a perspective view of the embodiment of FIG. 11;

FIG. 14 is a top schematic view of one embodiment of a device fordetecting a directional differential pressure in accordance with someembodiments;

FIG. 15 is a perspective view of the embodiment of FIG. 14;

FIG. 16 is a side view of one embodiment of a device for detecting adirectional differential pressure in accordance with some embodiments;

FIG. 17 is a top view of an alternative embodiment of a device fordetecting a directional differential pressure in accordance with someembodiments;

FIG. 18 is a top, cross-sectional view according to one embodiment;

FIG. 19 is a side, cross-sectional view according to one embodiment;

FIG. 20 is a front view of the embodiment of FIG. 19;

FIG. 21 is a partial view of a device for detecting a differentialpressure in accordance with some embodiments;

FIG. 22 is a partial view of another device for detecting a directionaldifferential pressure in accordance with some embodiments;

FIG. 23 is a partial view of a device for detecting a directionaldifferential pressure in accordance with some embodiments;

FIG. 24 is a partial view of a device for detecting a directionaldifferential pressure in accordance with some embodiments;

FIG. 25 is a partial view of a device for detecting a directionaldifferential pressure in accordance with some embodiments;

FIG. 26 is a partial perspective view of a holder used with a device fordetecting a differential pressure in accordance with some embodiments;

FIG. 27 is a cross-sectional view of the holder used with the device ofFIG. 26;

FIG. 28 is a partial cross-sectional view of a sound attenuator usedwith a device for detecting a directional differential pressure inaccordance with some embodiments;

FIG. 29 is a partial exploded view of the sound attenuator used with thedevice of FIG. 28;

FIG. 30 is a partial cross-sectional view of another sound attenuator inaccordance with some embodiments;

FIG. 31 is a partial cross-sectional view of another sound attenuator inaccordance with some embodiments;

FIG. 32 is a partial cross-sectional view of another sound attenuator inaccordance with some embodiments;

FIG. 33 is a cross-sectional view of another sound attenuator inaccordance with some embodiments;

FIG. 34 is a cross-sectional view of a device for detecting adirectional differential pressure in accordance with some embodiments;

FIG. 35 is an exploded view of the device of FIG. 34;

FIG. 36 is a partial cross-sectional view of a support used with adevice for detecting a directional differential pressure in accordancewith some embodiments;

FIG. 37 is a partial cross-sectional view of the support used with thedevice of FIG. 36 in a tilted orientation;

FIG. 38 is a cross-sectional view of another device for detecting adirectional differential pressure in accordance with some embodiments;

FIG. 39 is a perspective view of an adjustable portion of a device fordetecting a directional differential pressure in accordance with someembodiments;

FIG. 40 is a cross-sectional view of another device for detecting adirectional differential pressure in accordance with some embodiments;

FIG. 41 is a perspective view of another adjustable portion of a devicefor detecting a directional differential pressure in accordance withsome embodiments;

FIGS. 42-43 are cross-sectional views of yet another device fordetecting a directional differential pressure in accordance with someembodiments;

FIGS. 44-45 are cross-sectional views of another device for detecting adirectional differential pressure in accordance with some embodiments;and

FIG. 46 is a cross-sectional view of another device for detecting adirectional differential pressure in accordance with some embodiments.

DETAILED DESCRIPTION

The present disclosure relates to devices and systems which provide anindication of potential or actual directional air flow and/or whether aparticular degree of directional differential pressure exists betweenspaces (e.g., two neighboring rooms or a room and an adjacent corridor)separated by a barrier such as a wall. In some embodiments, the deviceincludes one or more elongated conduits with openings, for example,located at opposite ends. As described further herein, the conduit(s)may extend through the wall, and adjustability of the incline ofportions of the device may reside on both sides or a single side of thewall. At least one ball, or other movable element, is disposed within apassageway of the conduit and moves freely back and forth along at leasta portion of the length of the conduit. Restraints or end stops locatedat the ends or at other areas of the conduit to contain the ball withinthe conduit. The end stops may have openings that allow fluid (e.g.,air, gas, liquid, water vapor) to flow through the passageway of theconduit from one end to an opposite end.

Systems are available for detecting whether a differential pressurebetween two spaces (e.g., between a clean room and an adjacent corridor)is above a threshold pressure difference. In some conventional systems,an inclined single conduit passes from one space to another through awall, and a movable ball is placed in the conduit. On one side of thewall, for example the corridor side, the conduit has a lower region nearthe wall and a higher region away from the wall. Gravity pulls the balltoward the lower region of the conduit near the wall. As the pressure inthe clean room is raised higher than the corridor pressure, air pressureand/or air flow apply forces against the ball. Once the pressuredifference between the clean room and the corridor reaches a thresholdlevel, the force of the air against the ball overcomes the force ofgravity, and the ball moves to higher region of the conduit. Byobserving the presence of the ball in the higher region, a user canquickly see that the pressure difference between the two spaces equalsor exceeds the desired directional differential pressure thresholdlevel. To change the threshold pressure difference, the angle ofinclination of the conduit is adjusted such that the amount ofgravitational force on the ball in the direction of the conduit isadjusted. A greater incline of the conduit in which the ball travelsrequires a greater pressure differential between the two rooms toovercome gravity and move the ball from a lower to a higher region insome embodiments.

Applicant has appreciated that it would be beneficial to provide adifferential pressure monitoring system where the threshold value ofdirectional differential pressure detection is adjustable from one sideof the wall (or other barrier) and/or the system can account for thewall being out of plumb. In some embodiments, a monitoring systemincludes a pivot arm (or multiple pivot arms) on one side of the wall,and the pivot arm includes a set point indicator that measures an angleof inclination using gravity instead of a measured reference to anotherphysical structure. In some embodiments, the arrangement of the pivotarm relative to the system permits pivoting of the pivot arm within avertical plane. The pivot arm may include a conduit which contains amovable element.

By providing independent adjustment of the inclination of a conduit onone side of the wall, adjustments to the threshold directionaldifferential pressure level can be made without having to access thedevice on both sides of the wall. Such an arrangement can be especiallyhelpful when various protocols must be followed to enter a room beingmonitored.

The walls or other barriers on which the monitoring devices disclosedherein are being installed may be out of plumb, that is, not strictlyvertical. Applicant has recognized that in such circumstances, pivotarms with angle indicators and/or threshold pressure indicators mayprovide inaccurate information if the indicators are based on anassumption that the wall is plumb. Embodiments disclosed herein providearrangements where accurate threshold directional differential pressureadjustment can be achieved even when the device is installed on anout-of-plumb wall. For example, in some embodiments, a conduit with themovable element therein is adjustable from one side of the wall, theconduit is pivotable within a vertical plane, and a set point indicatoris tied to gravity rather than being based on markings on portions ofthe device that are static relative to the wall. A device that links athreshold set point to markings on the wall and/or markings on portionsof the device that do not move relative to the wall may cause errorswhen mounted to an out-of-plumb wall. Additionally, if a conduit doesnot pivot in a single plane, improper initial mounting of the device toa wall may cause inclination measurement errors.

In some embodiments, one or more levels, such as bubble levels, may beused to confirm proper device installation and/or to provide anindication as to set points that are based on the vertical inclinationof a conduit relative to the horizontal plane. In some embodiments, thebubble level, or other measurement device, is used as a directionaldifferential pressure set point indicator.

Certain embodiments disclosed herein provide a large range of availableinclination angles. By providing a large angle range, a large range ofthreshold differential pressure set points are available. In someembodiments, the device is also arranged to permit pivoting such thatthe conduit containing the movable element (e.g., a ball), can be placedin different orientations relative to its associated wall (or otherbarrier), in some cases while maintaining its same inclination relativeto a horizontal plane. In some embodiments, the conduit that isperpendicular to an axis of rotation may be rotated a full 360° aboutthe axis of rotation.

As mentioned above, various embodiments disclosed herein may include adirectional differential pressure set point indicator associated withthe conduit that contains the moveable element. The set point indicatormay be configured to correlate the incline of the conduit with respectto the earth's gravitational horizontal or vertical plane to arespective threshold directional differential pressure between the twoadjacent spaces—the threshold directional pressure difference beingsufficient to cause the movable element to move from a lower region ofthe inclined conduit to a higher region. The directional differentialpressure set point indicator may include, for example, a bubble vial, arotating weighted pendulum pointer, or any other suitable component thatresponds to the incline of the conduit. The differential pressure setpoint indicator may be appropriately calibrated such that the markingson the directional differential pressure set point indicator correspondto threshold directional pressure differences that may exist betweenspaces separated by a wall or other barrier. Accordingly, thedirectional differential pressure set point indicator may provide anindication of what angle of conduit inclination corresponds to thedirectional threshold differential pressure set point between the twoseparated spaces.

In some embodiments, when installed, a conduit extends from one side ofa barrier, e.g., wall to the other side such that opposite ends of theconduit extend outwardly into neighboring spaces that are separated bythe wall. In some embodiments, only one end of the conduit extendsoutwardly from the wall. Fluid (such as air) is permitted to flowbetween the spaces through the conduit in some embodiments. When theconduit is inclined, and there is little to no net differential pressurebetween the spaces to which opposite ends of the conduit extend, theforce of gravity acting on the ball causes the ball to move toward orremain at the lower end of the conduit.

In some embodiments, the incline of the conduit is such that the lowerend of the conduit is placed in the room desired to be of a higherpressure relative to the adjacent communicating room via the conduitwhere the higher end of the conduit resides. In this arrangement, thedesired direction of potential or actual air flow caused by thispressure differential will be from the higher pressure room with thelower end of the conduit toward the lower pressure room with the higherend of the conduit.

The pressure difference required to move the ball from a home position(the ball's position when there is no pressure difference between therooms) can vary based at least on the physical features of the conduit(e.g., passageway diameter, straightness/curvature, surface finish),physical features of the ball (e.g., diameter, weight, surface finish),degree of incline of the conduit, fluid properties of the media betweencompartments, and the orifice sizes at the end stops. In many cases,each of the above parameters is known to a sufficient degree such thatthreshold directional pressure differences can be linked to the angle ofinclination. In some embodiments, balls of different weights may be usedto adjust the threshold pressure differences. In such embodiments, theconduit angle may or may not be adjustable.

As an example, for a hospital isolation room occupied by a patient withan infectious disease that is capable of airborne transmission, it maybe desirable to keep the room at a negative differential pressurerelative to one or more adjacent rooms, so as to substantially preventairborne transmission of the disease to an adjacent room. In such anarrangement, the room's ventilation system exhausts more air than issupplied within it to an extent that the negative pressure is of agreater magnitude than any adjacent space. Thus, the conduit may beinstalled such that the end of the conduit that extends toward theisolation room (e.g., extends inside the isolation room) is at a higherposition than the opposite end of the conduit that extends toward aspace immediately exterior to the isolation room (e.g., into a corridor,a compartment, duct, or another room).

When the net directional differential pressure between the isolationroom and the outside space is zero (e.g., a door between the room andthe outside space is opened), or the pressure on the room is greaterthan the adjacent spaces, the ball will fall to the lower end of theconduit such that an observer inside the isolation room would not beable to view the ball; and where the opposite end of the conduit islocated within the neighboring room, it follows that an observer outsidethe isolation room in the neighboring room would be able to see theball. Or, if the conduit is substantially located within the isolationroom (e.g., in a turret-type configuration), the ball may fall to thelower end of the conduit yet remain within the isolation room (e.g.,exposed or covered from view), or within the wall cavity between rooms.When the appropriate degree of negative pressure is applied to the room,the ball moves upwardly within the conduit to the vertically higher end.That is, the difference between the pressure of the isolation room andthe pressure in the outside space on the opposite side of the wallcauses forces on the ball are sufficient to move the ball upwardly whereit can be conspicuously viewed from inside the isolation room—therebyindicating that at least the appropriate direction of air flow throughan opening between the rooms and degree of negative pressure is appliedto the isolation room.

In the case of a hospital operating room that is required to exhibit apositive pressure, so as to substantially prevent potentiallycontaminated air from flowing into a room from a surrounding spaces. Theconduit may be installed such that the end of the conduit that extendstoward the operating room (e.g., extends inside the operating room) isat a lower position than the opposite end of the conduit that extendstoward the surrounding space exterior to the room. Thus, when a suitableamount of positive pressure is applied to the operating room, there issufficient directional differential pressure to move the ball upwardlywithin the conduit to the conduit end toward the surrounding space.

As discussed above, it may be desirable to adjust the device fordifferent threshold differential pressures that give rise to respectivedirections of air flow between the spaces. If it is desired that themagnitude of the negative pressure difference between a room and theoutside space be increased, the conduit may be adjusted to be inclinedat a greater angle relative to a horizontal reference plane. Devicesdescribed herein may permit straightforward and convenient adjustment ofthe angle of the conduit relative to a horizontal reference plane, so asto provide a clear indication as to whether the newly desired netdifferential pressure exists to cause a desired potential or actualdirection of air flow between the separate spaces.

When installed, the conduit may be set at an appropriate angle ofinclination that corresponds to the desired threshold differentialpressure set point to cause a desired direction of air flow betweenseparate spaces. In some embodiments, the desired differential pressurebetween separate spaces to which the device may provide an indication ofthe appropriate degree of incline may be between 0.001 inch of H₂O and10 inches of H₂O (e.g., between 0.001 inch of H₂O and 1 inch of H₂O,between 0.001 inch of H₂O and 5 inch of H₂O, between 0.005 inches of H₂Oand 0.5 inches of H₂O, between 0.1 inch of H₂O and 0.5 inches of H₂O,between 0.01 inch of H₂O and 0.1 inches of H₂O, between 0.01 inch of H₂Oand 0.05 inches of H₂O, between 0.01 inch of H₂O and 0.03 inches of H₂O,between 0.005 inches of H₂O and 0.1 inch of H₂O, between 0.001 inch ofH₂O and 0.005 inches of H₂O, between 0.001 inch of H₂O and 0.003 inchesof H₂O, etc.), as measured by a standard water column manometer. It willbe appreciated that devices of the present disclosure may provide anindication of other differential pressures between adjacent spacesoutside of these ranges.

As discussed above, a differential pressure set point indicator may besecured to the conduit so as to provide a correlation between the angleof inclination of the conduit and the threshold differential pressurebetween the spaces.

As an example, if the desired differential pressure leading to air flowin a particular direction between compartments separated by a wall is0.02 inches of H₂O, then, given the components of the system (e.g.,ball, conduit, orifices), the conduit may be angled in such a mannerwhere the lower end of the conduit is toward the higher pressurecompartment and the higher end of the conduit is toward the lowerpressure compartment, that the force of gravity on the ball will beovercome by the pressure and any air flow forces on the ball in thedirection opposite gravity from the low to the high end of the conduit,created by at least 0.02 inches of H₂O pressure difference between thecompartments. Accordingly, if the angle of inclination of the conduit isset for a differential pressure of 0.02 inches of H₂O betweencompartments, and the differential pressure between the compartments isactually 0.01 inches of H₂O, then the amount of directional forces onthe ball generated by the only 0.01 inches of H₂O differential pressurein the direction from the lower end to the upper end of the conduit willbe insufficient to overcome the force of gravity on the ball, due to theangle of incline of the conduit being too large. The same holds if thedirection of potential or actual air flow within the conduit is from thehigher end toward the lower end caused by a reversal of the directionaldifferential pressure. As a result, the ball will remain at the lowerend of the conduit because the directional threshold differentialpressure in the desired direction of potential or actual air flow fromthe lower end to the higher end has not been met. However, if the angleof inclination of the conduit is lowered so as to correspond to a lower,0.01 inch of H₂O differential pressure in the desired direction of airflow between compartments, then the amount of directional differentialpressure and any air flow forces on the ball will be sufficient toovercome gravity and move the ball from the lower end to the higher endof the conduit.

Applicant has recognized that external calibration methods are used toestablish an accurate relationship between the angle of tilt of theconduit and the threshold differential pressure required to move theball from one end of the conduit to the other. For example, once thedevice is installed, such external calibration methods may include theuse of a manometer to measure the pressure differential between theadjacent spaces to which the device/conduit is coupled, and noting theangle of tilt of the conduit at which the ball moves from one end to anopposite end (e.g., falling from the higher end to the lower end, ormoving from the lower end to the higher end). To continue thecalibration process, the pressure difference between the adjacent spacesis adjusted and measured, and the corresponding angle of tilt of theconduit at which the ball moves from one end to the other is furthernoted. These steps of calibration are repeated for multiple pressuredifferentials and corresponding angles of tilt for the device. Suchsteps of pressure measurement and calibration may be expensive andtime-consuming.

One possible method to avoid re-calibrating a device each time it isinstalled to a wall involves including markings on the device thatcorrelate the conduit's angle of inclination directly to thedifferential pressure between spaces that causes the ball to move fromone end to the other. Applicant has recognized that such a method mayrely on the orientation of the wall to which the device is mounted orresides against, which might not be aligned with the direction ofgravity (i.e., the wall might not be plumb). That is, providing markingsthat indicate particular threshold differential pressure values thereonmay lead to inaccurate results unless the wall is vertically alignedwith the direction of gravity (i.e., the wall is plumb) and theindicator is properly installed to the wall.

Applicant has appreciated that it may be advantageous to employ anindicator that is directly calibrated to gravity. For example, aninclinometer that responds to the force of gravity (e.g., bubbleinclinometer, pendulum inclinometer, etc.) may be mounted to anappropriate portion of the differential pressure detection device sothat an accurate determination can be made as to the actual degree oftilt of the conduit required to reach an equilibrium between the forceof gravity and the forces on the ball, arising from directionaldifferential pressure across the ball resulting from the directionaldifferential pressure between the adjacent spaces. Accordingly, theaccuracy of such a device is not reliant on whether the wall to which itis mounted or otherwise resides against is aligned with the direction ofgravity (i.e., plumb).

Further, Applicant has recognized that it may be advantageous to be ableto adjust the angle of inclination of the conduit containing the ballfrom only one side of the wall while maintaining the conduit in a singleplane, for example, a vertical plane. When pivoting the conduit in onlya vertical plane, various inclinometers, such as a weighted ball, or aweighted pendulum, that are positioned at a given roll orientationrelative to a longitudinal axis of the conduit (e.g. on the top of theconduit) will remain positioned at the same roll orientation relative tothe conduit throughout pivoting of the conduit. In a device whereadjusting the vertical inclination requires a lateral inclination aswell, the weighted pendulum may have a roll component when the conduitis moved, which may re-orient the bubble vial to an orientation thatmakes reading difficult, or in some cases, prevents proper measurement.For example, if a conduit rotates only within a conical space (ratherthan a planar space), any change in vertical inclination results in arolling of the conduit about its own axis, which would change the rolland yaw orientation of the inclinometer, such as the weighted pendulum.As with some embodiments disclosed herein, when pivoting in a verticalplane is possible without requiring other reorientation, the weightedpendulum would only change its pitch orientation.

In further embodiments of the present disclosure, a device for detectingwhether a threshold directional differential pressure is present betweentwo spaces separated by a wall may include multiple conduits thatprovide a continuous passageway through which air may flow betweenspaces on opposing sides of the wall. In some cases, such arrangementsmay allow for the angle of incline of the conduit that contains themoveable element to be adjusted from one side of the wall, rather thanhaving to make adjustments to the angle of the incline of the conduit,coordinated from both sides of the wall.

For example, a conduit having at least one movable element (e.g.,lightweight ball) located therein may be arranged to extend along,parallel to, or be rigidly coupled to an axis that rotates about a pivotpoint, where rotation of the conduit about the pivot point is accessiblefrom one side of the wall. In some embodiments, the pivot point ispositioned on one side of the wall, or is offset a suitable distancefrom one side of the wall. For example, the pivot point may be locatedwithin a space outside of the wall (e.g., spaced away from an exteriorsurface of the wall) or within a space between exterior surfaces of thewall. In some embodiments, the conduit may rotate without a set pivotpoint. For example, the conduit may be configured to translate androtate at the same time.

In various embodiments, a first conduit may extend between the walls orwithin a wall, providing a passageway between the respective spacesseparated by the wall, similar to that described above with respect tosome embodiments. The first conduit may be a rigid tube or flexible hoseor combination thereof, installed in any fashion that allows fluidcommunication between the adjacent spaces. Here, the angle of incline ofthe first conduit with respect to a horizontal reference plane does notaffect the accuracy of the pressure detection, in contrast with otherconduits described herein, which extend from one side of the wall to theother side and are adjustable between various angles of incline.

A second conduit may be positioned at substantially one end of the firstconduit, extending the passageway through which air flows between spaceson opposing sides of the wall. In various embodiments, as discussedabove, adjustability of the angle of incline of the second conduit maybe accessible from one side of the wall, without having to access thesecond conduit from the other side of the wall. In some cases, thesecond conduit may be rotatable about a pivot point located on or nearone side of the wall. For example, the second conduit may have a freeend that extends away from the wall and an attached end that extendssubstantially toward the pivot point (e.g., located on the same side ofthe wall, within the wall cavity, or at another location).

Similar to that described with respect to various embodiments discussedabove, the angle of inclination of the second conduit with respect tothe horizontal or vertical plane may be employed in conjunction with oneor more movable elements to provide an indication as to whether adirectional differential pressure meeting a desired threshold existsbetween opposing sides of the wall.

When it is desirable for the device to provide an indication of theexistence of a different directional differential pressure thresholdbetween spaces separated by the wall, the angle of inclination of thesecond conduit may be suitably adjusted. This function is similar toembodiments of conduits described above, except in this embodiment,rather than having to adjust the angle of inclination of a conduit fromboth sides of the wall, the second conduit is able to be adjusted solelyon one side of the wall.

Such an arrangement makes adjustability of the device to provideindications of various directional differential pressure thresholds moreconvenient. For example, if it is desired that the magnitude of thepressure difference between a room and an adjacent space be increased,the second conduit may be adjusted to be inclined at a greater anglerelative to a horizontal or vertical reference plane.

The conduit(s) may include any suitable material. In some embodiments,the conduit(s) may be made up of glass, plastic, or another appropriatematerial. In some cases, the conduit(s) may be transparent ortranslucent so that the movable element within the conduit is viewableto an observer. In some embodiments, the conduit(s) are rigid, though,in various embodiments, the conduit(s) are flexible. The device mayinclude a combination of rigid and flexible conduits. A conduit need notbe cylindrical in shape as any suitable shape may be used.

Turning to the figures, FIG. 1 depicts a device 100 for detectingwhether a directional differential pressure is present between twospaces separated by a wall 50. The device 100 includes a conduit 110(e.g., tube) which has openings at opposite ends. Though, as notedherein, the openings are not required to be located at opposite ends ofthe conduit.

The conduit 110 extends from one surface 52 of a wall 50 to the oppositesurface 54. In this embodiment, the surface 52 corresponds to a firstroom 10 and the surface 54 corresponds to a second room 20 on theopposite side of the wall. The conduit 110 extends between neighboringrooms 10, 20 at an angle θ with respect to a horizontal reference planeh.

At least one movable element, such as a ball 120 (e.g., a ping pongball, other spherical ball, non-spherical object, etc.) or othersuitable article, is contained by end stops 130 (e.g., end caps) thatallow fluid flow through the end stop within a passageway of theconduit. The ball 120 has an outer diameter that is less than the innerdiameter of the conduit 110. In some embodiments, the ball is made of alightweight material and moves freely along the length of the conduit110 between opposite ends. Any other suitable movable element may beused, for example, a slidable block, a cylindrically shaped article,etc. In some embodiments, multiple movable elements may be used by thedevice simultaneously.

Each end of the conduit may be fitted securely with restraints or endstops 130. The end stops 130 have respective openings 132 through whichfluid (e.g., air) may readily flow. The openings 132 have respectiveshapes and sizes that prevent the ball from falling out of the conduitwhen the ball moves toward and impacts the end stop 130. For example,the opening 132 may have a diameter that is smaller than the outerdiameter of the ball 120, keeping the ball retained within thepassageway of the conduit.

The end stops 130 may be suitably secured as caps at the ends of theconduit 110, for example, by a friction fit, snap fit, or otherwise. Insome embodiments, the end stops 130 and the conduit 110 are transparentor translucent so that the ball 120, when present, can be readily seenby a person observing the device from either space 10, 20 on oppositesides of the wall 50 in which the device is installed. In some cases,the ball 120 is brightly colored so that the ball is easily noticeableto a person who is looking at the device.

The conduit 110 is attached to the wall by a series of wall flanges. Inparticular, FIG. 1 shows inner wall flanges 150 and outer wall flanges160, along with inner sealing materials 152 and outer sealing materials162. The flanges 150, 160 are appropriately positioned so as toaccommodate the desired angle of inclination of the conduit. The conduitis held by the outer sealing materials 162 at the desired angle ofinclination, described further below.

An inner sealing material 152 is disposed between an inner wall flange150 and the surface 52. The inner wall flange 150 and inner sealingmaterial 152 may be secured (e.g., attached, adhered, fastened) togetherto the wall surface 52. As such, the inner sealing material 152 mayprovide an appropriate seal, preventing unwanted air leakage betweenrooms 10, 20 via the wall cavity space, should such a cavity exist.Additionally, the inner wall flange 150 and inner sealing material 152have respective openings that are large enough through which the conduit110 may extend without contact.

Outer wall flange 160, in turn, is secured (e.g., attached, adhered,fastened) to the inner wall flange 150 with the outer sealing material162 being disposed between the flanges 150, 160. The outer wall flange160 and outer sealing material 162 have openings through which theconduit 110 may extend. The inner sealing material 162 provides anappropriate seal preventing unwanted air leakage between rooms 10, 20,or via a wall cavity space. However, in various embodiments, the openingof the outer sealing material 162 has a diameter that is less than theouter diameter of the conduit 110 so that an appropriate seal may beformed between the outer sealing material 162 and the conduit 110. Suchan arrangement further allows the conduit 110 to be suitably supportedand held in a steady position when installed at an angle.

The wall flanges 150, 160 and sealing materials 152, 162 may be attachedto respective wall surfaces 52, 54 and to each other by any suitablemethod, for example, via an adhesive and/or fastener. The wall flanges150, 160 and sealing materials 152, 162 may be adjustable in position soas to accommodate variations in the angle of inclination θ of theconduit. In some embodiments, the inner wall flange 150 is attached tothe wall 50; however, the position of the outer wall flange 160 may beadjusted vertically with respect to the inner wall flange 150.Accordingly, the outer wall flanges 160 may be re-positioned to permitthe angle of the conduit to be appropriately altered.

The device 100, when installed, may be used to detect whether a desireddirectional differential pressure exists between the separate rooms 10,20. When the air pressure between the separate rooms 10, 20 is the same,there will be no net flow of fluid through the conduit from one room tothe other. Therefore, if the conduit is held at an angle of inclinationwith respect to the horizontal, due to gravity, the ball will fall downtoward the lower of the two end stops and rest against that stop.

However, when the air pressure between the rooms 10, 20 is not equal,there will be a net flow of fluid through the conduit from the room witha comparatively higher pressure toward the other room. In FIG. 1, thepressure within room 10 is higher than the pressure within room 20.Accordingly, air will potentially flow in a direction from room 10 toroom 20, as indicated by the arrows shown within the conduit. If thedifferential pressure from room 10 to room 20 meets a certain threshold,the pressure and any air flow forces on the ball in the directionopposite gravity from the low to the high end of the conduit willovercome the force of gravity on the ball causing the ball to move fromthe lower end of the conduit within room 10 toward the higher end of theconduit within room 20. Thus, for the embodiment of FIG. 1, when theball moves from room 10, through the wall and into room 20, the devicehas indicated that the differential pressure between room 10 and room 20has met a certain threshold directional differential pressure causingpotential or actual air flow through the conduit to travel in thedirection from room 10 toward room 20.

In FIG. 2, there is no difference in pressure between the rooms 10, 20;hence, there is no potential pressure or any air flow forces on theball. Accordingly, because the conduit remains at a slight angle ofincline θ with respect to the horizontal h, the ball 120 rolls and/orfalls back to the lower end of the conduit, within room 10. In FIG. 1,the outer wall flange of room 10 is positioned substantially lower thanthe outer wall flange of room 20. Accordingly, the conduit 110 isoriented according to a relatively steep angle. Though, in FIG. 2, theouter wall flange of room 10 is positioned to be in much closeralignment, vertically, with respect to the outer wall flange of room 20.Such positioning permits the conduit 110 to be oriented according to amuch smaller angle of incline.

Other arrangements are possible. For example, as discussed furtherbelow, a device may include an angled conduit where only one end extendsoutwardly from a wall, rather than two ends. Accordingly, depending onthe differential pressure between spaces, the ball may move between avertically higher region of the conduit and a vertically lower region ofthe conduit within the same room, or at least partially within a wallcavity.

In some embodiments, the device includes a differential pressure setpoint indicator that provides an indication (e.g., via a pointerreferencing various markings) of a minimum differential pressurethreshold that would cause the ball to move from a lower end regiontoward a higher opposite end region of the conduit. Markings of thedifferential pressure set point indicator may refer to actual units ofpressure indicating the directional threshold pressure differential setpoint between rooms. Markings may include alphanumeric values to which acorrelating table may be referred, to determine the correspondingdirectional threshold differential pressure set point. Or, in someembodiments, markings of the differential pressure set point indicatormay provide the actual inclination angle θ of the conduit with respectto a horizontal reference plane h, also to which a correlating table maybe referred, to determine the corresponding directional thresholddifferential pressure set point.

The differential pressure set point indicator may include a suitablepointer that senses the true gravitational horizontal or vertical plane(e.g., via an air bubble within a liquid, a ball within a fluid, a tippointer, a pendulum, a pivotally arranged member, a weighted member,etc.) and associated markings that, when referred to by the indicator,provide information regarding the angle of inclination of the conduitand corresponding directional threshold differential pressure set point.The markings may be calibrated such that steady alignment of theindicator with a particular region of the markings, resulting in aparticular angle of incline of the conduit, provides an indication to anobserver of the threshold differential pressure required to cause theball to move from a lower region to a higher region of the conduit.

It may be desirable for the device to provide assurance to an observerthat the direction of air flow and the associated differential pressurebetween separate spaces meets certain requirements. For example, thedifferential pressure requirement in a particular direction betweenneighboring rooms may be approximately 0.01 inches of H₂O, and thedirectional differential pressure set point indicator may have markingsthat, given a particular angle of incline of the conduit, correspond tothe different levels of differential pressure required to createsufficient forces to cause the ball to move from a lower region (e.g.,lower end) to a higher region (e.g., higher end) of the conduit. In thisexample, upon installation or adjustment of the device, the conduit maybe set at a particular angle θ such that the pointer or bubble or ballof the differential pressure set point indicator comes into steadyalignment with markings that correspond to a 0.01 inches of H₂O pressuredifferential. Accordingly, when the actual differential pressure betweenrooms is approximately 0.01 inches of H₂O or above, the pressuredifference and any air flow forces on the ball will be sufficient toovercome the force of gravity on the ball so as to move the ball towardthe higher end of the conduit.

When the directional differential pressure between rooms degrades (e.g.,a door/window is opened between rooms or the ventilation system airflows degrade from proper settings), then the directional differentialpressure between rooms may fall below approximately 0.01 inch of H₂O inthe direction from the lower end to the higher end of the conduit, andthe ball falls back to the lower end of the conduit due to gravity,indicating to an observer that the minimum directional differentialpressure is not present. In some embodiments, when the directionaldifferential pressure between rooms inadvertently falls below thedesired directional threshold pressure differential, an alarm may soundalerting the appropriate personnel that the direction of air flow or thedirectional threshold differential pressure requirements of the room arenot met.

It may be desirable to have an adjustable range of differential pressureset points to accommodate different requirements between neighboringrooms, which may be accomplished by adjusting any of the associatedcharacteristics of the elements of the detector, e.g., the ball diameterand weight, the conduit passageway diameter, the end stop orifices, theincline of the conduit. For example, there may be a desired directionalair flow and associated threshold differential pressure of 0.05 inchesof H₂O, from a previous setting of 0.01 inches of H₂O. As a result,given all other elements of the detector unchanged, the angle of inclineof the conduit should be adjusted appropriately. If the conduit remainsat the angle corresponding to a differential pressure of 0.01 inches ofH₂O, then an actual directional pressure difference between rooms of,for example, 0.03 inches of H₂O in the same desired direction would givean observer an erroneous indication that the directional thresholddifferential pressure between the rooms is at least 0.05 inches of H₂O.That is, for this example, the forces generated by a directionaldifferential pressure of 0.03 inches of H₂O would cause the ball to moveupward within the conduit, despite the desired directional thresholddifferential pressure of 0.05 inches of H₂O.

Accordingly, the angle of incline of the conduit may be re-positioned ata different angle such that the pointer of the directional thresholddifferential pressure set point indicator comes into steady alignmentwith markings that correspond to a 0.05 inches of H₂O directionalthreshold pressure differential. Thus, only when the actual directionaldifferential pressure between rooms is 0.05 inches of H₂O or above, theforces generated by the pressure difference will be sufficient toovercome the force of gravity on the ball so as to move the ball towardthe higher end of the conduit. If and when the differential pressurerequirement between neighboring rooms is to be changed yet again, thenthe angle of incline of the conduit may be further re-positioned to adifferent orientation that corresponds to the updated thresholddirectional differential pressure desired, according to the read outprovided by the directional differential pressure set point indicator.

Single Side Adjustment

FIGS. 3-7 show embodiments of a device that provides an indication of athreshold directional differential pressure existing between spacesseparated by a wall where adjustability of the inclination is on oneside of the wall. The embodiments shown in FIGS. 3-7 include aturret-type arrangement.

As shown in FIGS. 3-5, device 100 includes a turret portion 170, a yokeportion 180 and a terminal portion 190. In this embodiment, the turretportion 170 is coupled to the yoke portion 180 to provide a rotatablehousing for the conduit 172 to be suitably inclined. The yoke portion180 may, in turn, be coupled with the terminal portion 190 to form apassageway through the wall cavity between otherwise separate spaces.The yoke portion 180 includes structure suitable for the adjustable partof the device 100 to be attached to or otherwise installed at one sidesurface 52 of the wall. That is, the angle of inclination of the device100 may be adjusted from only one side of the wall. In variousembodiments, the yoke portion 180 may include a mounting flange 184 thatmay be appropriately secured against or interfaced with one side 52 ofthe wall, for example, via a fastener, interference fit, interlockingarrangement, or other suitable method. To ensure suitable alignment ofthe device against the wall and in the vertical (gravitational)direction, structure members such as shims or adjustable standoff screwsmay be optionally employed with the mounting flange, as desired.

Similarly, the terminal portion 190 includes structure suitable for thedevice 100, upon installation, to form a passageway through the wallcavity 50. For instance, the terminal portion 190 may include a mountingflange 194 that may be appropriately secured against or interfaced withthe other side 54 of the wall, such as with a fastener, interferencefit, interlocking arrangement, etc. Any suitable arrangement may be usedfor installing and holding the device in place across the wall cavity 50(e.g., solid wall, space between wall surfaces). As further shown, theterminal portion 190 further includes an opening 196 that allowsfluid/air to flow between the passage 198 and the room 20.

FIG. 4 shows the device 100 installed and, in this embodiment, the yokeportion 180 includes an extension 182, and the terminal portion 190 alsoincludes an extension 192. The extensions 182, 192 may complement oneanother or otherwise extend toward one another so as to optionally meet.Such extensions may provide support for a first conduit 112 in extendingthrough the wall between separated spaces 10, 20, allowing fluid (e.g.,air) to flow therebetween. As shown, one end of the first conduit 112 iscoupled to one side 52 of the wall via the yoke portion 180. The otherend of the first conduit 112 is coupled to the other side 54 of the wallvia the terminal portion 190. The coupled unit including the firstconduit 112 and extensions 182, 192 provide a passage 198 through whichfluid (e.g., gas, liquid, etc.) may flow between rooms 10, 20. Theconduit 112 may be secured to the extensions 182, 192 via any suitablemanner, for example, through an adhesive attachment,interlocking/interference fit, threaded configuration, etc.

It can be appreciated that other configurations for suitably securing aconduit 112 in place may be possible. That is, it is not necessary forthe yoke portion 180 or terminal portion 190 to include extensions 182,192 as the conduit 112 may extend across the wall cavity 50 (e.g., solidwall, space between wall surfaces, etc.) without an arrangement whichincludes respective extensions 182, 192. In some embodiments, while notexpressly shown in the figures, the yoke portion 180 and/or terminalportion 190 may include corresponding receptacles—each having a couplingregion for interfacing with respective ends of the conduit 112. Forinstance, the yoke portion 180 and/or terminal portion 190 may include arespective recess shaped or otherwise configured to receive and secure acorresponding end of the conduit 112 thereto. In some cases, the recessmay be lined with a gasket to maintain a seal between the internalpassage of the conduit and the external environment.

The yoke portion 180 may include a yoke body 186 that interfaces and isrotatably coupled with the turret body 176 of the turret portion 170. Asshown, the yoke body 186 may include a receptacle for receiving theturret body 176, and the turret body 176 may rotate and/or pivot withinthe receptacle. The yoke body 186 also includes a passage 188 thataccommodates fluid flow therethrough between the passage 178 within theturret body 176 and the passage 198. As further depicted in FIGS. 4-5,the yoke portion 180 may optionally include a gasket 181 for maintaininga seal at the interface between the yoke body 186 of the yoke portion180 and the turret body 176 of the turret portion 170.

As shown, a second conduit 172 may be attached or otherwise coupled withthe turret body 176 so as to be rotatable about a pivot axis A, whichmay be provided by an appropriate connection between the yoke body 186and the turret body 176. It can be appreciated that the second conduit172 may be pivotally or rotatably coupled to the yoke body in otherways. For instance, the second conduit itself may function as a pivotingturret, without requiring a rotatable housing (i.e., turret body)through which the second conduit may be coupled to the yoke body. As anexample, the second conduit may directly be rotatably or pivotallycoupled to a support structure (e.g., yoke body) via a pivotingattachment without need for a housing (e.g., turret body) to carry theconduit. Any suitable pivoting attachment may be employed, for example,a pivot pin/axle and/or fastener (e.g., wingnut) for tightening thepivoting attachment between the conduit and the support structure.

In some embodiments, a region and/or component (e.g., inclinometers) ofthe yoke portion may provide an indication as to whether the pivotitself is appropriately aligned or oriented according to the horizontalreference plane h, as determined by gravity, so that the device providesaccurate readings. That is, such an arrangement allows the movableelement or ball to translate along linear paths within the conduit thatare consistent at various angles of inclination.

The second conduit 172 may be coupled with the turret body 176 in anysuitable manner. For some embodiments, as shown, the turret body 176 mayinclude a conduit receptacle 174 having a recess for receiving an end(e.g., attachment end) of the conduit 172. The conduit receptacle 174may optionally include a retainer 171 and/or a fastener 179 for suitablyholding the conduit 172 in place so that the conduit 172 is secured tothe turret body 176. The end stop 173 may also serve to hold the conduit172 in place. The retainer 171, end stop 173 and/or fastener 179 mayinclude any appropriate structure or configuration. For example, theretainer 171 and/or end stop 173 may include a rubber gasket thatprovides resistance to movement of the conduit 172 when situated withinthe receptacle. Or, the fastener 179 may include a threaded rod that maybe sufficiently turned so as to push up against the conduit 172 and keepthe conduit secured in place upon establishing a suitable amount ofcontact force therebetween. As depicted, the opposite end (e.g., freeend) of the second conduit 172 may extend away from the pivot axis A,and the wall. The turret body 176 may further include a passage 178which, in concert with passages 188, 198, permits the fluid (e.g., gas,liquid, etc.) to flow between rooms 10, 20.

As shown, the second conduit 172 may be arranged so as to rotate about apivot point and along a substantially vertical plane, having a pitchwithout appreciable horizontal offset or yaw. In some embodiments, suchrotating motion may be such that the conduit rotates within the sagittalplane extending through the apparatus.

In accordance with aspects of the present disclosure, the conduit 172may include one or more balls 120, or other movable element(s), whichmay provide an indication as to whether a particular differentialpressure threshold exists between separated spaces on either side of thewall, as determined by the angle of incline θ of the conduit 172. Forexample, the ball(s) 120 may be adapted to move back and forth withinthe conduit 172 depending on the fluid flow through the device 100 thatresults from the direction and amount of differential pressure betweenthe rooms 10, 20. In accordance with aspects of the present disclosure,when the conduit 172 is tilted at an angle with respect to thehorizontal or vertical reference plane, absent net fluid forces on theball 120, the ball 120 falls by force of gravity to the lower free endof the conduit 172. Though, given a sufficient amount of forces on theball 120, from the lower free end of the conduit toward the higher end(e.g., due to a net pressure differential), the force of gravity on themovable element may be overcome such that the ball 120 moves toward thehigher end of the conduit.

Similar to embodiments described herein, the end stops 130, 173 may belocated at opposite ends of the conduit 172 and may, at least in part,be provided as cushioning for the ball 120 as it comes into contact withrespective ends of the conduit. In accordance with the presentdisclosure, for some embodiments, the ends stops 130, 173 include anenergy-absorbing material (e.g., elastomeric material, polymer, rubbergasket, etc.) that attenuates sound upon contact of the ball 120.Without such energy-absorbing capability, an audible sound (e.g., whentwo relatively hard surfaces come into contact) may be distinctly heard.In some cases, such a sound may be distracting and it may be preferablefor the sound to be substantially eliminated or reduced.

As discussed above, the turret, along with the conduit 172, may beconfigured to pivot or otherwise rotate about the yoke body along avertical plane (e.g., sagittal plane) of the device 100. In variousembodiments, such a configuration may be beneficial so that the ball 120or other movable element may be suitably aligned with the opening 132 atthe free end of the conduit 172. As described herein, for someembodiments, the center axis of the opening 132 may be slightly offset adistance d from the center axis of the conduit 172, yet substantiallyaligned with a travel path of a center of the ball 120 or other movableelement. That is, an axis perpendicular to a center of opening 132 maybe substantially the same as the path of the center of ball 120, and theaxis may be offset from the center axis of the conduit 172. In thismanner, the ball aligns with the opening 132 at the end of the conduitand may prevent air flow through the opening 132. In embodiments wherethe conduit pivots in only a vertical plane, the ball may align with theopening in all angles of conduit inclination. Such a configuration mayprovide an added amount of stability for the ball 120, reducing thelikelihood that the ball 120 spins or migrates from the opening throughwhich fluid/air flows.

Though, it can be appreciated that it is not required for the turret topivot along the sagittal plane. In some embodiments, while not shown inthe figures, the turret is configured to rotate so as to exhibitadjustments in pitch and yaw. For example, rotation of the turret mayinvolve movement of the end of the conduit in an approximately circularor ellipsoidal path.

Similar to that described with respect to other embodiments of thepresent disclosure, the device may include a protective covering 380surrounding the turret. The protective covering 380 includes an opening382 through which fluid may flow between rooms 10, 20 via the conduits112, 172 and passages 178, 188, 198. In various embodiments, theprotective covering 380 fits over the wall flange 184 and may includeany suitable sealing material that may be associated therewith.

In accordance with aspects of the present disclosure, any suitabledifferential pressure set point indicator may be employed. As shown, adifferential pressure set point indicator 200 is provided as aninclinometer which is mounted or otherwise located on the turret portion170, in alignment with the inclination of the second conduit.Accordingly, the inclinometer is rotatable along with the conduit 172and provides an indication as to the amount of pitch that exists in theorientation of the conduit 172. The angle of inclination of the conduit172 is correlated to a threshold differential pressure between the twospaces that is sufficient to cause the ball 120, or other movableelement within the conduit, to move from one region (e.g., a verticallylower position) of the conduit toward an opposite region (e.g., avertically higher position) of the conduit. In some embodiments, asshown, the inclinometer is attached to a rotatable turret which rotatesboth the conduit 172 and the inclinometer together as a unit.

FIG. 5 is an exploded view of an illustrative embodiment of a device 100where various types of differential pressure set point indicators 200may be employed. In this figure, indicators (e.g., inclinometers withball or bubble pointers) similar to those depicted in FIGS. 21-25 areprovided, though, it can be appreciated that any suitable indicator maybe employed. In various embodiments, the differential pressure set pointindicator 200 includes a coupling region 240 which may, in turn, have astructure that corresponds to a complementary coupling region 242 of theturret portion 170. In this embodiment, the coupling region 240 of theindicator 200 includes a slot, and the coupling region 242 of the turretportion 170 includes a protruding ridge along which the slot may slide.Hence, the indicator 200 may slide along the ridge of the turret portion170 for suitable coupling therewith. While not expressly shown in thefigures, the indicator 200 may be suitably attached or otherwise securedto the turret portion 170, for example, via a fastener, interferencefit, or other appropriate arrangement.

In some embodiments, the device 100 optionally may include markings anda pointer which provide an indication as to the desired setting forthreshold pressure differential between spaces separated by the wallbased on the inclined angle θ of the conduit 172. Such markings andpointer may act as a suitable differential pressure set point indicator.For instance, in the embodiment illustrated in FIG. 3, the turret body176 includes markings 220 and the yoke body 186 includes a pointer 222extending therefrom. In some cases, the markings 220 may indicate unitsof pressure. Here, the markings 220 and pointer 222 correlate the levelof incline of the conduit 172 with the threshold pressure differentialrequired between opposing spaces to cause the movable element to travelfrom a lower position of the conduit to a higher position.

In some embodiments, to accentuate the markings, a number of detents(e.g., respective recesses/protrusions) may be provided, for example,between the yoke body and the turret. Each detent position maycorrespond to an angle θ at which the conduit 172 is inclined which, inturn, corresponds to a particular threshold differential pressure acrossthe wall that is sufficient to cause lift of the movable element at thatparticular angle of incline.

In some embodiments, the device may be configured so as to providedesired directional differential pressure threshold values that arecalibrated against the true gravitational horizontal or vertical “plumb”planes of the earth. This provides for a greater degree of accuracycompared to a non-gravity sensing set point indicator that is coupled toa device and calibrated to a plumb vertical plane, where the indicatoris mounted on a wall that is assumed to be installed “plumb,” yet infact may be significantly out of plumb and therefore indicatingpotentially significant inaccurate directional differential pressures.Accordingly, even if the wall upon which the device is installed is notperfectly vertical, the device still, within an acceptable tolerance,may provide an accurate indication of the threshold level of pressuredifferential required between rooms to move the ball between opposingends of the conduit.

In various embodiments, the device 100 may include inclinometers 202,204, which may provide an indication as to whether the device 100 itselfis tilted. For instance, as shown in FIGS. 3-5, the inclinometers 202,204 may be located on the yoke body 186, optionally positionedperpendicular with respect to one another. Here, a first inclinometer202 indicates whether the yoke body 186 exhibits any variation in pitch,and the second inclinometer 204 indicates whether the yoke body 186exhibits any variation in roll. Accordingly, during installation, theinclinometers 202, 204 may provide an indication as to whether the uppersurface of the yoke body is level. For some embodiments, while not shownin the figures, a single inclinometer may be mounted on to the yoke body186 and oriented diagonally, so as to provide an indication as towhether the yoke body 186 is suitably level (e.g., zero pitch and zeroroll).

In certain embodiments, for a yoke body 186 that is suitably level, themarkings 220 on the turret body 176 that are in alignment with thepointer 222 of the yoke body 186 may indicate the threshold differentialpressure required to move the ball 120 between opposing ends of thesecond conduit 172. Though, if the first inclinometer 202 indicates thatthe yoke body 186 exhibits a non-level pitch with respect to gravity,then the threshold differential pressure indication provided by themarkings 220 and pointer 222 may be inaccurate. If the secondinclinometer 204 indicates that the yoke body 186 exhibits a non-levelroll which may also affect the pitch of the conduit 172, the ball 120might not be suitably aligned within the conduit 172 to be able to forma suitable seal with the orifice of end stop 130 when located at the endof the conduit. When this seal between the ball 120 and the orifice 132remains malformed, movement of the ball 120 within the conduit 172 aswell as the pointer markings may be unreliable and inaccurate.Accordingly, for various embodiments, it may be preferable for theinclinometers 202, 204 to indicate that the device 100 is sufficientlylevel to provide an accurate reading of the threshold differentialpressure between spaces required to move the ball between end positionswithin the respective conduit. If preferred or required, the orientationof the device (e.g., pitch, roll, yaw) can be corrected, for example, byusing structural elements, such as shims and/or adjustable standoffscrews, etc.

The device 100 may include a detector 600 which provides an indicationas to where the ball 120 or other movable element is located within theconduit 172. For example, as depicted in FIG. 3, the detector 600 mayinclude a sensor 610 and an arm 620 on which the sensor is mounted. Insome embodiments, the sensor 610 may be a photodetector, motion sensoror camera that detects whether an object is located along the directionin which the sensor is oriented. For example, when the ball is locatedat the free end stop 130 of the conduit 172, the amount of lightreceived by the sensor 610 may be altered (e.g., reduced) as compared towhen the ball is located at the mounted end stop 173. Upon receiving athreshold change (e.g., reduction) in light, the detector may provide anindication that the ball is located at the free end of the conduit 172.

As further shown in FIG. 5, the detector 600 may include a couplingregion 630 which may, in turn, have a structure that corresponds to acomplementary coupling region 632 of the turret portion 170. Here, thecoupling region 630 of the detector 600 includes a T-shaped ridge andthe coupling region 632 of the turret portion 170 includes a slot forreceiving the corresponding T-shaped ridge. Thus, the detector 600 mayslide along the slot of the turret portion 170 for suitable couplingtherewith. It can be appreciated that the detector 600 may be suitablyattached or otherwise secured to the turret portion 170 or other part ofthe device 100 through any appropriate arrangement, for example, via afastener, interference fit, etc.

Other arrangements for detecting the location of the ball or othermovable element within the conduit 172 may be possible. For example, thedetector may include a suitable tactile sensor that detects contact fromthe ball or other movable object within the conduit, indicating thelocation thereof.

When the humidity of the surrounding environment is relatively low,there may be a tendency for triboelectric-electrostatic charge to buildup at various regions of the device. For example, low humidity airpassing through the conduit and over the ball may give rise toelectrostatic build up. An accumulation of static discharge may affectthe accuracy of the device in providing an indication of whether athreshold of directional differential pressure is met. For example, themovable element may be attracted to or repulsed from a particular regionwhere electrostatic charge has built up. Thus, in such instances,gravity acting on the movable element might not be the only force to beovercome by potential differential pressure and air flow forces on theball.

Accordingly, in some embodiments, one or more of the conduits of thedevice may be lined with a conductive material 700 (e.g., metallining/band) which may, in turn, be connected to a ground 710. Such aconductive material 700 may itself act as an electrical ground thatserves to dissipate electrostatic charge build-up in and/or around thedevice which may be otherwise undesirable. The conductive material mayinclude a metal strip, anti-static coating, other suitable materials, orcombinations thereof.

FIGS. 6-7 show various embodiments of the device 100 where the pressuredifference between rooms 10, 20 generates an amount of pressure andpotential air flow forces on the ball 120 sufficient to move the ball120 from a lower end to a higher end. As described herein, the device100, when installed, may be used to detect whether a desired directionaldifferential pressure exists between the separate rooms 10, 20. When theair pressure between the separate rooms 10, 20 is the same, there willbe no net potential flow of fluid through the conduit from one room tothe other, and the ball drops toward the lowest point within the conduit172 due to gravity.

FIGS. 6-7 depict schematics of when the air pressure between the rooms10, 20 is not equal, resulting in a potential of net flow of fluidthrough the conduit 172. As shown, in FIG. 6, the turret portion 170 andconduit 172 are rotated downwardly to provide an indication of whetherthe pressure in room 10 is greater than the pressure in room 20 by athreshold amount. In FIG. 7, the turret portion 170 and conduit 172 arerotated upwardly to provide an indication of whether the pressure inroom 20 is greater than the pressure in room 10 by a threshold amount.

In FIG. 6, the pressure within room 10 is higher than the pressurewithin room 20. Hence, pressure forces and potential air flow forces onthe ball 120, potentially move the ball in a direction from room 10 toroom 20, as indicated by the arrows shown within the conduit 172. If theforce generated by the differential pressure and potential of air flowfrom room 10 to room 20 meets a threshold value sufficient to overcomethe force of gravity on the ball, the ball will then move from the lowerend of the conduit 172 toward the higher end of the conduit 172.

Thus, for the embodiment of FIG. 6, when the ball 120 moves from the endstop 130 (located at a lower position) to the end stop 173 (located at ahigher position), the device provides an indication that thedifferential pressure between rooms 10, 20 has met a correspondingthreshold differential pressure In some embodiments, the receptacle 174extends away from the turret body 176 by a sufficient distance such thatthe ball 120 is covered by the wall of the receptacle 174 as it comes upagainst the end stop 173, so that the ball is substantially hidden fromview. Accordingly, for this embodiment, when the ball 120 is moved so asto be shrouded by the receptacle 174, it can be determined that at leasta threshold differential pressure between rooms 10, 20 exists.

In the embodiment shown in FIG. 7, the pressure within room 20 is higherthan the pressure within room 10, causing air to potentially flow in adirection from room 20 to room 10, as indicated by the arrows. Similarto that with respect to FIG. 7, if the force generated by thedifferential pressure and potential of air flow from room 20 to room 10meets a threshold value sufficient to overcome the force of gravity onthe ball, the ball will then move upward within the conduit 172.Accordingly, as depicted in FIG. 7, upon movement of the ball from theend stop 173 (located at a lower position) to the end stop 130 (locatedat a higher position), the device provides an indication that thedifferential pressure between rooms 10, 20 has met a correspondingthreshold differential pressure.

In some embodiments, fluid flow may not exist through the device. Forexample, a movable element may be sized to match the inner diameter ofthe conduit and have a low friction interface such that the movableelement can move within the conduit without fluid flowing past themovable element. In this manner, according to some embodiments, theremay be a fluidic connection that is only a fluidic pressure connectionbetween the spaces on either side of a dividing wall, and the movableelement may move in response to a pressure difference, but no air willbe transferred from one space to the other through the monitoringdevice. Such a device may include a piston-type arrangement.

As provided herein, the device may include multiple conduits. Forexample, a first conduit may be located on one side of the wall and asecond conduit may be located on the opposite side of the wall. In someembodiments, the angle of inclination of the first conduit on one sideof the wall is adjustable independently from the angle of inclination ofthe second conduit on the other side of the wall. Alternatively, theangle of inclination of respective conduits on opposing sides of thewall may be adjusted together, dependent upon one another. For instance,when the angle of inclination of a first conduit on one side of the wallis adjusted, the angle of inclination of the second conduit on the otherside of the wall may also be adjusted to match the new angle of thefirst conduit, or may remain different from the angle of inclination ofthe first conduit.

Differential Pressure Set Point Indicators

A number of different differential pressure set point indicatorssuitable for use with embodiments disclosed herein will now bedescribed.

FIGS. 8-9 show a device with an interchangeable bubble differentialpressure set point indicator 200. Each bubble differential pressure setpoint indicator has a vial containing a liquid and an associated bubble.When the bubble reaches a steady equilibrium alignment between the linedmarkings on the vial, the differential pressure set point indicator isconsidered to be level with respect to the horizontal.

As shown, any one of a series of bubble differential pressure set pointindicators 200 a, 200 b, 200 c may be appropriately secured to theconduit. Each bubble differential pressure set point indicator 200 has abase plate 214 constructed for appropriate attachment to a surface ofthe conduit. The bottom surface of each base plate 214 is sloped so thatwhen the respective differential pressure set point indicator isinstalled, the bubble will attain steady alignment between the linedmarkings when the conduit is set at a particular angle of incline. Thatis, the conduit will be positioned at an angle of incline that willallow the bubble of the differential pressure set point indicator tosteadily remain within the middle of the vial between the linedmarkings. Such an angle of incline will correspond to the desiredthreshold differential pressure between separate spaces that would causethe ball to be displaced from the lower end toward the higher oppositeend.

Referring to FIGS. 8-9, the currently installed differential pressureset point indicator 200 a corresponds to a threshold differentialpressure of 0.03 inches of H₂O (IWC). Accordingly, when the conduit isinstalled at the appropriate angle where the bubble of the differentialpressure set point indicator 200 a remains steadily at the middle of thevial, a directional differential pressure between rooms of 0.03 inchesof H₂O or greater in the direction that causes air to flow in thedirection from the lower end to the higher end of the conduit and willgenerate enough forces to cause the ball to move from room 10 to room20. Hence, if the directional differential pressure between rooms isless than 0.03 inches of H₂O in the direction from room 10 to 20 or thedirectional differential pressure goes to zero or reverses, then thepressure differential and potential air flow forces on the ball will beinsufficient to overcome the force of gravity on the ball. In such acase, the ball will remain at the lower end of the conduit.

The differential pressure set point indicator 200 a may be appropriatelyreplaced with either of differential pressure set point indicators 200b, 200 c which, in this illustrative example, correspond to thresholdpressure differentials of 0.02 inches of H₂O and 0.01 inches of H₂O,respectively. Thus, if the device is fitted with differential pressureset point indicator 200 b, when the conduit is installed at an anglesuch that the bubble pointer of the differential pressure set pointindicator 200 b remains steadily at the middle of the vial, adirectional differential pressure between rooms of 0.02 inches of H₂O orgreater in the direction from room 10 to 20 will cause the ball 120 tobe moved from room 10 to room 20. And if the differential pressurebetween rooms is less than 0.02 inches of H₂O in the direction from room10 to 20 or the directional differential pressure goes to zero orreverses, then the pressure differential and potential air flow forceson the ball will be insufficient to overcome the force of gravity on theball.

As shown in FIG. 8, the indicator 200 senses the degree of incline ofthe conduit 110. The bottom surface of base plate 214 for attachment ofdifferential pressure set point indicator 200 a (corresponding to athreshold directional differential pressure of 0.03 inches of H₂O) tothe conduit has a slope that is greater than that of differentialpressure set point indicator 200 b which, in turn, has a slope greaterthan that of differential pressure set point indicator 200 c.Accordingly, for the differential pressure set point indicators of FIGS.8-9, a greater desired threshold differential pressure will require agreater degree of slope of the conduit

An embodiment of a device fitted with an adjustable bubble differentialpressure set point indicator is shown in FIG. 10. Like other bubbledifferential pressure set point indicators, this differential pressureset point indicator includes a vial 210 with a liquid and associatedbubble pointer 212. The vial may be appropriately rotated about a pivot230 with a fastener (e.g., wing nut), capable of loosening and securingrotation of the vial about the pivot so that the vial points to markings220 that indicate corresponding threshold differential pressure valuesthat may be set between separate spaces which, in turn, correspond tothe appropriate angle of inclination of the differential pressure setpoint indicator 200 and, hence, the angle of the conduit 110 itself whenthe bubble pointer 212 is between the boundary lines 213. For instance,when it is desired for the device to be installed so as to extendthrough a wall and between rooms to indicate to an observer that adirectional differential pressure of at least 0.02 inches of H₂O ispresent, then, in the embodiment of FIG. 10, the angular position of thevial on the pivot 230 is adjusted so that the vial 210 points to theparticular marking that references a pressure of 0.02 inches of H₂O inthe desired direction of potential air flow. The desired direction ofpotential air flow is determined by placing the low end of the conduitin the room of desired higher pressure relative to the other room wherethe high end of the conduit resides. Since the differential pressure setpoint indicator can sense both directions of the conduit incline, theremay be similar symmetric markings for the desired threshold differentialpressure set point in each direction. Accordingly, the device isappropriately installed such that the pointer of the vial 210 alignswith the appropriate directional differential pressure markingsresulting in the conduit having an angle of inclination that allows thebubble pointer 212 to remain steady at the middle of the vial betweenthe boundary lines 213. Hence, after appropriate installation, adirectional differential pressure in the direction from room 10 to room20 of 0.02 inches of H₂O or greater will generate enough pressuredifferential and potential air flow forces on the movable element tocause the ball to move from room 10 (lower end) to room 20 (higher end).

If it is further desired that the device provide indication to anobserver of whether a directional different differential pressurebetween rooms is present, then the pivot can be appropriately adjustedso that the vial points to the appropriate one of the two similarmarkings which correspond to the desired pressure, of which theappropriate mark of the two is determined by adjusting the conduitincline with the low end in the desired higher pressure room and thehigh end in the desired lower pressure room so that the bubble 212reaches an equilibrium state in the middle of the vial e.g., betweenboundary lines 213.

For example, a change in the desired pressure difference between thespaces from 0.02 inches of H₂O to 0.03 inches of H₂O with the samedesired direction of potential air flow may involve a simple adjustmentof the wing nut so that the vial 210 points to the closer marking thatreferences 0.03 inches of H₂O, which would involve positioning theconduit at a steeper angle of incline to put the bubble 212 in betweenthe boundary lines 213. Once the differential pressure set pointindicator is appropriately adjusted and the angle of inclination of theconduit is set within the wall such that the bubble pointer 212 remainssteady at the middle of the vial, the device is now ready to provide anaccurate indication of whether the desired direction of potential airflow and directional threshold differential pressure between rooms isactually present.

Adjustable Angle of Inclination

Described below are additional embodiments of monitoring devices whichmay be adjustable from one side of a wall. The embodiments describedbelow may use various levels and/or differential pressure set pointindicators, including embodiments described above. The embodimentsdescribed below may provide large ranges of inclination angles forsetting threshold pressure differences. In some embodiments,adjustability is possible on both sides of the wall. “Single sideadjustment” does not exclude embodiments where adjustability is possibleon both sides. Instead, the term is intended to include a device wherean aspect of the device on one side of a barrier (such as a wall) isadjustable without necessarily resulting in or requiring adjustment of aportion of the device on an opposite side of the wall.

FIGS. 11 and 12 show a top view and a perspective view, respectively, ofone embodiment of a monitoring device. According to this embodiment, apivot arm may be pivotable about a horizontal axis to adjust a pitchangle, and the pivot arm additionally may be pivotable about a verticalaxis to adjust the yaw angle of the pivot arm. The device is bracedagainst a first side 402 of a wall and a second side 404 of the wallusing mounting flanges 406 on the exterior of each side of the wall. Invarious embodiments, the device may be supported in a wall, door,window, or any suitable barrier between a first space (such as a room401) and a second space 403, such as an external environment 403. Thefirst side 402 of the wall is associated with the room 401 having afirst air pressure, and the second side 404 of the wall is associatedwith the external environment 403 having a second air pressure. Themounting flanges 406 are connected with a first conduit 400 that extendsthrough at least a portion of the wall. The conduit length may beadjustable to conform to the distance between the first side 402 of thewall and the second side 404 of the wall.

An end of the first conduit 400 may be pivotally connected to one faceof a swivel base 414 such that the swivel base 414 may rotate ±90° (ormore or less in some embodiments) from a home position to adjust the yawangle of the swivel base 414 about an axis 413. The interface betweenfirst conduit 400 and swivel base 414 may have an opening that fluidlyconnects the flow passageway of the first conduit 400 to a flowpassageway of the swivel base 414. In some embodiments, the flowpassageway within the swivel base 414 bends perpendicularly such thatthe flow path begins on a first face of the swivel base 414 and ends ona second face of the swivel base 414 that is adjacent to the first face.

A pivot arm 408 is pivotally attached to swivel base 414 such that thepivot arm 408 may rotate about a horizontal axis 407. A transparentwindow 410 portion of the pivot arm 408 includes a ball 412 (or othermovable element) that moves in response to pressure differences betweenthe two spaces separated by the wall.

The swivel base 414 may have a level 416 attached to aid in checkingwhether the device is correctly set in the wall in terms of a rollcomponent. In one embodiment, the level 416 may use an air bubble inliquid to indicate whether the device is oriented correctly. Additionallevels may be placed at other suitable locations to help with checkingpitch and yaw orientations of the device. For example, in addition to,or instead of, level 416, a level 421 may be included on the device toverify whether pivot arm 407 is horizontal.

By using levels to confirm the horizontal orientation of the pivot armaxis, the device can compensate for a wall (or other barrier) that isnot plumb. In embodiments where there is a rotating base, placing thelevel on the rotating base can also allow the device to compensate forout-of-alignment structure between the wall and the rotating base.

The pivot arm 408 is attached to the swivel base with a cylindricalconnector 411 in this embodiment. A cylindrical insert is attached toswivel base 414 and is received by a corresponding cylindrical recess onpivot arm 408. Such an arrangement allows for a wide range ofinclination angles according to an aspect of things disclosed herein. Insome embodiments, the pivot arm 408 may be adjustable by ±90° relativeto horizontal about axis 407. In other things, pivot arm 408 may bepivotable in only one direction. For example, pivot arm 408 may beadjustable between 0° and +90°. In some embodiments, pivot arm 408 maybe adjustable by at least ±30°, ±45°, ±60°, ±75° or 360°.

The yaw angle of the pivot arm 408 may be adjusted by rotating theswivel base 414 about an axis 413. By adjusting the yaw angle, theorientation of the pivot arm relative to the wall can be tailored todesired position. For example, the arrangement shown in FIG. 12 may beused when a user is looking along the length of a corridor at thedevice. Rotating the swivel base 414 by 90° counterclockwise from a topview reorients the transparent window 410 so that the ball 412 is easilyvisible when viewing the device from in front of the wall.

The interface between the swivel base 414 and pivot arm 408 may fluidlyconnect the flow passageway of the swivel base 414 with one end of aflow passageway that extends through the pivot arm 408. On the other endof the pivot arm 408, the flow passageway may connect with a flowpassageway that extends through transparent window 410. The transparentwindow 410 may have an opening that exposes the flow passageway to theair pressure of the room 401.

In a room with positive differential air pressure, air may flow from theroom 401 to the external environment 403. In a room with negativedifferential air pressure, air may flow into the room 401 from theexternal environment 403. Embodiments described herein may establish aflow passageway between the room 401 and the external environment 403using the first conduit 400, the swivel base 414, the pivot arm 408, andthe transparent window 410. Within the flow passageway formed by thepivot arm 408 and the transparent window 410, ball 412 may move in andout of the transparent window, depending on the strength and directionof air flow.

For a positive pressure room 401, the pivot arm 408 may be pitcheddownward to correspond to a chosen differential pressure. Rotating thepivot arm 408 downward increases the force needed to push the ball 412or other pressure indicator from the transparent window 410 and towardthe pivot arm 408. A positive differential air pressure may move thepressure indicator to a stationary position in the pivot arm 408. Notviewing the pressure indicator may indicate that the room 410 has theappropriate positive air pressure. If the pressure indicator is visiblewithin the optically transparent portion of the pivot arm 408, the airpressure may be below the pressure for which the device is calibratedand the user may be alerted.

For a negative pressure room 410, the pivot arm 408 may be pitchedupward to correspond to a chosen pressure. Rotating the pivot arm 408upward increases the force needed to push the pressure indicator 412from the pivot arm 408 and toward the transparent window 410. A negativedifferential air pressure may move the pressure indicator to astationary position in the transparent window 410. Viewing the pressureindicator may indicate that the room 401 has the appropriate negativeair pressure. If the pressure indicator is not visible within thetransparent window 410, the room air pressure is higher than thepressure for which the device is calibrated and the user may be alerted.In one embodiment, the pressure indicator may be a ball or some othereasily movable object.

In another embodiment shown in FIGS. 14 and 15, no swivel base 414 maybe present such that the pivot arm 408 is directly connected to thefirst conduit 400 to establish a fluidic pressure connection. Thisconfiguration may reduce the space that the device occupies, as thepivot arm 408 is parallel to the first side 402 of the wall. As with theprevious embodiment shown in FIGS. 11 and 12, the device is supported ina wall by mounting flanges 406 on a first side 402 of a wall and on asecond side 404 of the wall. The first side 402 of the wall faces into aroom 401 with a first air pressure.

On the first side 402 of the wall, the conduit 400 is pivotallyconnected to pivot arm 408. The pivot arm 408 may pivot ±90° to controlthe air pressure differential monitoring calibration. In someembodiments, the pivot arm may pivot 360°. The flow passageway continuesat the interface of the base 400 and the pivot arm 408 and through thepivot arm 408. In one embodiment, the flow path in the pivot arm 408 maybend perpendicularly to change direction.

At the end of the pivot arm 408, a transparent window 410 continues theflow passageway from the pivot arm 408. The end of the transparentwindow 410 may be open or only partially sealed so the flow passagewayis exposed to the first air pressure of the room. Ball 412 may move intothe transparent window 410 portion of the pivot arm depending on the airpressure differential between the room and the external environment 403.

The pivot arm 408 may have a level 419 attached to aid in checkingwhether the device is correctly set in the wall in terms of a pitchcomponent. In one embodiment, the level 419 may use an air bubble inliquid to indicate whether the device is oriented correctly. Forexample, if the wall is not plump, the device may be shimmed orotherwise adjusted until the level 419 shows that the device is level.In this manner, pivot axis 407 can be verified to be horizontal.

A transition region 417 exists where the passageway is first surroundedby the pivot arm when traveling in a direction toward the pivot arm. Insome embodiments, the transition region is where a cylindrical recesssurrounds a cylindrical insert. In the embodiment shown in FIG. 15, theconduit 400 may extend slightly into a cylindrical recess (not shown) inpivot arm 408 where the outer surface of conduit 400 engages with aninner surface of the cylindrical recess. This engagement region would bethe transition region in such an embodiment. In some cases, such as inthe embodiment of FIG. 15, the pivot arm is arranged such that pivotingthe pivot arm within the vertical plane does not change a location ofthe transition region relative to the first conduit. In someembodiments, such as the embodiment of FIG. 15, pivoting the pivot armdoes not alter the flow passageway from the conduit to the pivoting arm.For example, the general path that fluid flow would follow to arrive atthe pivot arm would not be altered when the pivot arm is pivoted. Inthis manner, significant changes to air flow resistance in thepassageway may be limited, yielding a more accurate reading device.

The embodiment of FIG. 15 may have a level 427 similar to level 419 ofFIGS. 13-14 to verify that the pivot axis 407 is horizontal.

FIG. 16 is a side view of one embodiment that includes an inclinometer414 and a level 416 to improve calibration and ease of use. As in theprevious embodiments, the device is supported in a wall that separates aroom 401 with a first air pressure and an external environment 403 witha second air pressure, though the device may separate other spaces. Thefirst conduit 400 may be fluidly connected to a pivot arm 408 thatpitches ±90° about a pivot axis 407 to control the air pressuredifferential monitoring calibration. On the pivot arm 408, theinclinometer 414 has gradations that indicate values of differentialpressure. The inclinometer may have an internal indicator that moves tomark a measured differential pressure. In some embodiments, theindicator may be a ball, a bubble in fluid, or some other movable meansof indicating. In other embodiments, the available range of inclinedangles may be different than ±90°. For example, the pivot arm may beable to pivot ±60° or ±45°.

The inclinometer may provide a visual signal of what differentialpressure the device is calibrated to measure. If the pivot arm 408 istilted upward, the pressure indicator 412 is biased toward the rear ofthe pivot arm 408 and out of the transparent window. In the case of anegative pressure differential, the upward tilt requires an adequatedifferential pressure to move the pressure indicator 412 back to thetransparent window 410 against the force of gravity. Because theinclinometer points to a different gradation depending on the tilt ofthe pivot arm, the inclinometer provides a straightforward method ofviewing the differential pressure for which the device is set, and forchanging the set point.

A level 416 may be mounted to the first conduit 400. The level 416 maybe used check that the pivot axis 407 is horizontal, that is, in thisembodiment, that the pivot arm 408 and inclinometer 414 travel in avertical plane. Level 416 verifies the roll of conduit 400 is in acorrect orientation. A non-horizontal pivot axis could render theinclinometer readings inaccurate or render the inclinometer inoperable.An additional level oriented similar to the level 427 shown in FIG. 15may be included to keep the device oriented correctly even if there isan out of plumb wall or out of plumb device.

FIG. 17 is a top view of an alternative embodiment. As in previousembodiments, the conduit 400 of the device is mounted in a wall thatseparates a room 401 with a first pressure from an external environment403 with a second pressure. Conduit 400 provides a fluidic pressureconnection between the mounting flanges 406. A pivot arm 408 ispivotally attached to the first conduit 400. The pivot arm 408 may haveextended portions at opposite sides.

As in previous embodiments, a flow passageway through the pivot arm 408fluidly connects the pivot arm 408 to the flow passageway of the firstconduit 400. The flow passageway continues into a transparent window410. As in previous embodiments, the pivot arm 408 may be pitched ±90°to set the device for a given air pressure differential threshold. Apressure indicator 412 may move within the flow path of the pivot arm408 and the transparent window 410. Exterior to the terminal end, thetransparent window 410 may have a photoeye 420 that detects the pressureindicator 412 or the absence of the pressure indicator 412. In oneembodiment, the photoeye 420 may comprise an electronic sensor thattriggers an alarm that the differential pressure is incorrect when thepressure indicator 412 is absent or present, depending on theconfiguration. In some embodiments, the electronic sensor may activate alight or other visual cue regarding the presence of ball 412 (or othermovable element) indicating that the threshold pressure differential isbeing met. A second light may be activated when ball 412 is absent,indicating that the threshold differential pressure is not being met. Asdescribed elsewhere herein, the absence of ball 412 may indicate thatthe threshold pressure is being met, while the presence of ball 412 mayindicate that the threshold pressure is not being met, and the sensorsand visual indicators may be configured correspondingly.

The flow passageway from conduit 400 to pivot arm 408 may be through oneor both of pivot connections 423. Connections 423 may be cylindricalconnections where a cylindrical insert engages a cylindrical recess, andone component rotates relative to the other.

FIG. 18 is a sectional top view of one embodiment of a pressuredifferential monitoring device. As in previous embodiments, the deviceis mounted to a wall using mounting flanges 406 on a first 402 andsecond side 404 of a wall. The mounting flanges 406 are attached to afirst conduit 400, which is pivotally connected at one end to a pivotarm 408. The pivot arm 408 has a transparent window 410 at one end. Thebase 400, pivot arm 408, and transparent window 410 are fluidlyconnected with a flow path. The end of the flow path at the transparentwindow 410 is partially sealed and exposed to a first air pressure in aroom. The end of the flow path at the second side 404 of the wall may beopen or partially sealed such that the passageway is exposed to anexternal environment with a second air pressure.

FIG. 19 is a side, sectional view of a further embodiment, and FIG. 20is a front view of the embodiment of FIG. 19. Pivot arm 408 of thedevice shown in FIGS. 19 and 20 is arranged to rotate 360° about ahorizontal pivot axis that is generally perpendicular to the wall. Insome embodiments, the pivot arm may rotate in both directions—clockwiseand counterclockwise. If the wall is not plumb, the flange 406 may beshimmed or otherwise adjusted such that the axis of rotation ishorizontal. A level, such as a bubble level 416 in FIGS. 17, 18, 19, maybe provided to check the horizontal plane pitch orientation of theconduit 400. A level also may be used to check the roll orientation ofthe pivot arm 408 so that pivot arm rotates in a vertical plane.

Marks 424 may be provided to indicate angles and/or thresholddifferential pressure levels associated with the angle of rotation ofpivot arm 408. An arrow 425 or other mark may be provided on a rotatingportion of the pivot arm to show which threshold differential pressurelevel is being set.

Differential Pressure Set Point Indicators

Additional embodiments for differential pressure set point indicatorsare described below. These differential pressure set point indicatorsmay be used with the various embodiments of monitoring devices disclosedherein.

FIG. 21 shows a device that includes a bubble differential pressure setpoint indicator. In this embodiment, the differential pressure set pointindicator 200 is attached to the conduit, 110 via an appropriate baseplate 214, and includes a vial 210 that contains liquid and anassociated bubble pointer 212. Due to the geometry of the vial andgravity acting on the liquid within the vial, the bubble moves to thehighest possible point within the vial. Here, the vial 210 exhibits ageometry (e.g., curvature) that allows for the bubble to providedifferential pressure set point information at multiple regions alongthe vial. For instance, when the conduit is perfectly level, the bubblemoves toward a position where the vial and base plate correlate to beinglevel. However, when the conduit is tilted at an angle, the position ofthe bubble relative to the vial will change, so as to provide anindication that the conduit is set at a different angle of incline.

Accordingly, appropriate markings 220 are provided adjacent to the vialso that appropriate differential pressure set point information can beprovided to an observer (e.g., someone who is adjusting the tilt of theconduit) when the conduit is angled in a manner that brings the bubbleinto steady alignment near particular marking(s). Since the differentialpressure set point indicator can sense both directions of the conduitincline, there are two similar symmetric markings for each desiredthreshold differential pressure set point. Here, the markings 220 referto the threshold directional differential pressure between roomsrequired to generate enough differential pressure and potential air flowforces to move the ball from the lower end of the conduit to the higherend. That is, the conduit 110 may be tilted so that the bubble pointer212 aligns with the appropriate one of the two similar markings whichcorrespond to the desired pressure, of which the appropriate mark of thetwo is determined by adjusting the conduit incline with the low end inthe desired higher pressure room and the high end in the desired lowerpressure room so that the bubble 212 remains in steady alignment andpointing to the desired marking that indicates a particular value of thedirectional pressure differential. When the conduit is installed at theangle that corresponds to that particular value of pressuredifferential, movement of the ball 120 to a higher region of the conduitmay provide assurance to an observer that the directional differentialpressure indicated by the bubble 212, at a minimum, actually existsbetween the separate spaces.

FIGS. 22-23 show devices that include a weighted ball-type differentialpressure set point indicators where the differential pressure set pointindicator 200 includes a vial 210 with a weighted ball pointer 212. Thevial 210 is filled with a fluid (e.g., gas, liquid) and the ball pointermoves to the lowest point within the vial by force of gravity. The vial210 may exhibit a curvature that permits the ball to provide informationregarding the angle of incline of the conduit when the ball 212 remainsin steady alignment at various regions along the vial. For instance,when the conduit is perfectly level, the ball pointer 212 moves towardthe middle of the vial. Though, when the conduit is tilted at an angle,the ball pointer 212 may still remain in steady alignment with a regionof the vial that is offset from the middle of the vial.

Markings 220 are provided adjacent to the vial so that appropriateinformation can be provided when the conduit is tilted such that theball pointer 212 steadily aligns with a particular set of the markings.The markings 220 refer to the threshold directional differentialpressure set point between rooms required to create a sufficient degreedifferential pressure and potential air flow forces that moves the ball120 within the passageway of the conduit 110 from the lower end of theconduit to the higher end. That is, the conduit 110 may be tilted sothat the ball pointer 212 aligns with markings that indicate aparticular value of directional pressure differential. When the conduitis installed at the angle that corresponds to that particular value ofdirectional pressure differential, movement of the ball 120 within thepassageway from the lower end of the conduit to the higher end of theconduit may provide assurance to an observer that the directionaldifferential pressure indicated by the ball pointer 212, at a minimum,actually exists between the rooms.

FIGS. 22 and 23 are various embodiments of ball-type differentialpressure set point indicators 200 where the shape of the vial differs.Depending on how the vial of a ball-type differential pressure set pointindicator is shaped, the markings 220 which relate the angle of inclineof the conduit to the threshold pressure differential(s) between roomswill be calibrated and appropriately positioned.

The ball-type differential pressure set point indicator of FIG. 22provides for different threshold differential pressure set points. Sincethe differential pressure set point indicator can sense both directionsof the conduit incline, there are two similar symmetric markings foreach desired threshold differential pressure set point. The ball-typedifferential pressure set point indicator of FIG. 23 provides forthreshold differential pressure information for tilt of the conduit inonly one direction, and so the markings may be unidirectional. In someembodiments, the ball-type differential pressure set point indicator ofFIG. 23, as compared to, for example, that of FIG. 22, provides for afiner degree of set point adjustment for indicating whether thethreshold differential pressure between rooms is present.

In the embodiment of FIG. 24, the device 100 includes a differentialpressure set point indicator 200 having a weighted pointer 210. Asshown, the differential pressure set point indicator 200 is rigidlysecured to the outer surface of the conduit 110 via base plate 214. Thedifferential pressure set point indicator 200 includes a tip pointer 212that is pivotally connected to the base plate 214. A weight 218 isprovided at an end opposite the tip pointer below the pivot point 216.When the conduit 110 is placed within a wall at an angle of inclinationwith respect to the horizontal, the tip pointer 212 will vary in itsposition and pivot to reflect the degree to which the conduit is tiltedwith respect to the horizontal.

The tip pointer is further adapted to rotate about the pivot point so asto point to the bi-directional reference markings 220, which arecalibrated to match the angle of incline with the threshold differentialpressure between opposite ends of the conduit 110 at which the ball 120will be urged against the force of gravity to move from the lower endtoward the opposite higher end of the conduit. As such, depending on theangle of incline of the conduit, the tip pointer will come into steadyalignment with reference markings 220 that are calibrated to representminimum differential pressures required to move and maintain the ball120 at a desired position within the conduit, for instance, at thehighest point.

FIG. 25 shows a device 100 that includes a pendulum directionaldifferential pressure set point indicator 200. The differential pressureset point indicator 200 is rigidly secured to the outer surface of theconduit 110 via base plate 214. The differential pressure set pointindicator 200 includes a pendulum pointer 212 that is pivotallyconnected to the base plate 214 at a point 216. Here, the pendulumpointer 212 extends downwardly and rotates about the pivot point 216 soas to point to the bi-directional reference markings 220 which arecalibrated similarly to that described above regarding FIG. 24.

Thus, given a desired minimum differential pressure between enclosedspaces that are separated by a wall through which the conduit extends,appropriately calibrated differential pressure set point indicators withaccurate markings may allow the angle of inclination of the conduitaccording to the present disclosure to be easily adjusted to suit thedesired directional pressure differential. That is, the conduit of adevice installed into a wall separating two enclosed spaces may beoriented at a particular angle that corresponds to a thresholddifferential pressure between the separate spaces sufficient to cause aball, or other movable element, disposed within the conduit to move fromthe lower end to the higher end of the conduit. When it is desired forthat threshold differential pressure between the separate enclosedspaces to be altered, the differential pressure set point indicator,with appropriately calibrated reference markings, may be used as an easyreference to determine what the adjusted angle of the conduit should beto correspond to the new threshold pressure differential.

Such an adjustment of the angle of the conduit may be a relativelysimple procedure. For instance, in some embodiments, fasteners attachingrespective outer wall flanges 160 to inner wall flanges 150 of thedevice may be loosened and the outer wall flanges, which provide supportfor the conduit, may be shifted vertically with respect to the innerwall flanges so as to suitably alter the angle of incline of theconduit. An appropriately calibrated differential pressure set pointindicator may be used as a reference to determine what angle of inclineto which the conduit should be set so as to correspond to the desiredthreshold differential pressure between opposite ends of the conduit.Once the conduit is oriented in accordance with the appropriate angle ofincline, the fasteners of respective outer wall flanges are thentightened to set the conduit firmly in place. Respective gaskets securedto the outer wall flanges may assist in holding the conduit securely atthe desired orientation.

Suitable adjustments of the angle of incline of the conduit may beperformed manually or automatically. For example, an operator may usethe above procedure to adjust the angle of incline of the conduitmanually.

Or, the device may be set up in accordance with an automated system thatis configured to adjust orientation of the conduit automaticallydepending on the desired level of differential pressure between spaceson opposite sides of the wall. In some embodiments, the device may beconfigured with a control system that automatically adjusts the angle ofincline of the conduit according to input provided by a user, or relatedcomputer system, of a desired differential pressure to be establishedbetween neighboring spaces. For example, a user may simply input theminimum differential pressure that is required between two rooms into auser interface and the system may automatically, without further userinteraction, adjust the angle of incline of the conduit to correspond tothe desired minimum differential pressure between rooms. In some cases,the control system may refer to the differential pressure set pointindicator by any suitable detection method, to determine the appropriateangle of incline of the conduit.

As discussed, physical features other than the incline of the conduitmay provide an indication of whether the directional differentialpressure between spaces meets a certain threshold.

For instance, the type of ball placed within the passageway of theconduit may be chosen based on particular characteristics, such asweight or surface finish of the ball. That is, a greater differentialpressure will be required to move a heavier ball from a lower region ofthe conduit to a higher region of the conduit. Conversely, if the ballis lighter, a smaller differential pressure will be required to move theball toward the higher end of the conduit. Alternatively, a ball havinga rough surface finish may require a greater degree of air flow providedthrough differential pressure to move the ball toward the higher end ofthe conduit. Accordingly, different balls, or movable elements, may bemarked according to the range of differential pressure that thedetector, incorporating the particular ball(s), may indicate.

Alternatively, the type of stops at the ends of the conduit may bechosen according to the particular range of directional differentialpressure(s) to be detected. For example, for a given ball within theconduit, an end stop having a small orifice that limits the exposedsurface area for which pressure acts on the ball from outside of theconduit when the ball is closing or mating with the end stop or limitsthe rate of air flow through the conduit may be used as an indicator forthe differential pressure between the spaces. That is, where end stopsof a detector have relatively small openings such that the exposedsurface area for which pressure acts on the ball from outside of theconduit when the ball is closing or mating with the end stop or limitsthe rate of air flow through the openings is limited, a greaterdifferential pressure will be required to move a ball from a lowerregion of the conduit to a higher region of the conduit. Conversely, ifthe openings are wider, allowing a greater surface area or exposed ballto the environment when mating with the end stop or a great flow rate ofair through the conduit, a smaller differential pressure may be requiredto move the movable element toward the higher end of the conduit. As aresult, different end stops having different orifice sizes may be markedaccording to the range of differential pressure that the detectorincorporating the particular end stop(s), may indicate.

Thus, different components of the differential pressure detector may bemarked so as to provide an indication of the minimum differentialpressure threshold that would cause the movable element to move from alower end region toward a higher opposite end region of the conduit.Markings of the ball, conduit, end stops of the conduit, etc. may referto actual units of pressure indicating the directional thresholdpressure differential set point between rooms; such markings may bealphanumeric values to which a correlating table may be referred;alternatively, the markings may provide an actual property (e.g., ballweight, end stop orifice size, conduit curvature, conduit/ball surfacefinish, etc.) to which a correlating table may be referred, to determinethe corresponding directional threshold differential pressure set point.

A differential pressure set point indicator may be secured to anyportion of a device using any suitable manner. In some embodiments,differential pressure set point indicators are secured to a device(e.g., on the outer surface of the conduit) by an appropriate adhesiveor fastener. Or, as discussed below, an appropriate holder may be usedto mount the differential pressure set point indicator.

FIGS. 26 and 27 show an embodiment of a holder 300 for mounting thedifferential pressure set point indicator 200 on to the conduit 110. Theholder 300 includes a plate 310 to which a surface of a differentialpressure set point indicator may be attached. The holder 300 furtherincludes an elastically deformable spring clip 320 that wraps around theexterior of the conduit 110. In some embodiments, the spring clip 320has an opening 330 with ends that may be spread apart so that theconduit 110 may be suitably secured within the clip 320. As analternative, a split ring divided at one or more locations along thering, capable of fastening tight about the perimeter of the conduit maybe used to mount the differential pressure set point indicator.

Sound Attenuation

In another aspect of the present disclosure, it may be desirable fornoise to be attenuated upon impact of the ball, or other movableelement, against either end stop that is useful for keeping the movableelement contained within the conduit. For instance, the ball and endstops of the device may be made of materials that produce a noticeablesound when the ball drops on to an end stop at the lower position orwhen the ball is pushed up against the end stop at the higher position.For example, a ping pong ball makes a distinct noise upon impact with arelatively rigid surface. In some cases, such a sound may be irritatingto people that may be located within either of the rooms that share thedevice. Thus, a sound attenuator or device may be included forsubstantially reducing noise when the ball moves from one end of theconduit to the opposite end and is subject to impact.

The sound attenuator may include any suitable material or combination ofmaterials. In some embodiments, the sound attenuator may include arelatively soft energy-absorbing material, such as an elastomer, rubber,neoprene, silicone, plastic, polymer, foam, fibrous material, paper,tissue, netting, etc. In some embodiments, the sound attenuator mayexhibit a geometry that cushions the impact of the movable element on astop.

In some embodiments, a sound attenuator separate from the end stops isfitted with the end stop(s) of the conduit, as shown by way of example,in FIGS. 28, 29, 30, and 32. In other embodiments, the end stop(s)include an energy-absorbing material which is sound attenuating and,hence, comprise the sound attenuator, for example, shown in FIG. 31.

FIGS. 28-29 show conduit 110 with an end stop 130 that forms a suitablefit (e.g., interference fit, snap fit) over an edge 111 of the conduit.Positioned between the edge 111 of the conduit and the end stop 130 is asound attenuator 140. In this embodiment, the ball 120 is a ping pongball and the end stop 130 is made of a hard plastic. Thus, withoutappropriate placement of the sound attenuator 140 between the conduitand the end stop, when the ball impacts against the end stop 130, anabrupt sound is produced which can be easily heard by a person locatedin the room where the impact occurs, and possibly in an adjacent roomwhere the other open end of the conduit resides. When the soundattenuator 140 is appropriately placed between the conduit and the endstop, impact of the ball against the sound attenuator 140 will produce amuch softer sound which is not as readily noticeable as compared withthe sound produced when the energy-absorbing material is not present.

FIG. 30 depicts another embodiment of an end stop 130 associated with asound attenuator 140. Here, the sound attenuator 140 is attached (e.g.,adhered) to the inside surface of the end stop. The sound attenuator ismade of a material that is shaped in a geometry that absorbs impactenergy. Accordingly, when the ball impacts the sound attenuator 140, arelatively soft sound is produced as compared to instances where theenergy-absorbing material in an energy-absorbing geometry is notpresent.

As shown in FIGS. 28-30, a center axis 122 of the opening of the soundattenuator 140 and the opening of the end stop 130 is offset from thecenter axis 124 of the conduit. The center axis 122 is substantiallyaligned with a path 124 along which a center of the ball 120 travels.Such alignment of the opening of the sound attenuator with the center ofthe ball aid in lessening the amount of sound generated upon impact atthe end(s) of the conduit than would otherwise be the case without thealignment. Additionally, alignment of the opening of the end stop and/orsound attenuator may prevent air flow through the conduit (via theopening of end stop 130) when the ball is positioned at the end of theconduit. That is, the alignment may contribute to having the ball orother movable element form a seal and limit the transfer of air betweenrooms whenever the ball abuts the end stop or sound attenuator.

By having the pivot arm of various embodiments herein pivot only in asingle plane (e.g. a vertical plane), the path of the center of the ballmay align with the opening in the end stop in many or all of thepossible inclinations of the pivot arm. Such an arrangement may allowthe ball to close the opening when it reaches an end stop. Another endstop may be positioned in the conduit closer to the wall such that whenthe ball moves toward the wall, it contacts the end stop. This secondend stop may have a sound attenuator and/or an opening as with end stop130.

In some embodiments, there may not be an alignment of the travel path ofthe center of the ball and an opening at the end of the conduit. Forexample, an interior-facing portion of an opening at the end of theconduit may be arranged and positioned such that the movable elementsubstantially prevents air flow when the movable element abuts theinterior-facing portion of the opening, yet a center axis of the opening(e.g., the centroid of the area of the opening) is not be aligned with atravel path of a center of the movable element. A ramp may be presenttoward the end of the conduit such that the movable element is pushed upinto the opening. In some embodiments, an axis perpendicular to thecentroid of the opening is downwardly offset from a center axis ofconduit. In embodiments where the conduit pivots only in the verticalplane, such an arrangement may permit the movable element to seal theconduit in sound, most, or all of the inclination angles of the conduit.

In some embodiments, the end stop itself is sound attenuating. As shownin FIG. 31, the end stop 130 includes an energy-absorbing material. Insome embodiments, the end stop may exhibit a geometry similar to adiaphragm. As a result, a softer sound is produced when the ball impactsthe sound attenuating end stop as compared to an arrangement where theend stop was made of a relatively hard plastic.

FIG. 32 shows a device where a sound attenuator 140 (e.g., grommet) isfitted at the opening of the end stop 130. The sound attenuator mayattenuate sound that would otherwise be produced upon impact of the ballagainst the end stop of the conduit. In some embodiments, the soundattenuator is flexible so as to be removable from the opening of the endstop and subsequently replaced. In some embodiments, such as shown inFIG. 33, the sound attenuator includes a flexible flap 142 surrounding aspace 144 that includes air and/or a soft material that absorbs theimpact of the ball. In other embodiments, the sound attenuator isintegrally formed with or permanently attached to the end stop.

Protective Covers

FIG. 34 shows a device 100 in an installed configuration where theconduit is positioned at an angle with respect to the horizontal. Theball 120 rests against a replaceable sound attenuator 140, provided as agrommet which is, in turn, coupled to the end stop 130. The devicefurther includes protective coverings 380 surrounding each end of theconduit. The protective coverings 380 include openings 382 through whichfluid (e.g., air, gas) may flow from one room 10, through the conduit,and to the room 20 on the other side of the wall. The protectivecoverings 380 are shown in this embodiment to fit over the wall flange160 and the associated sealing material 162 in a secured manner, withthe edge of the coverings being in contact with the wall flange 150.

Protective coverings may be useful to shield the openings of theconduit, or the ball itself, from contamination or sudden rushes of airthat may affect positioning of the ball within the conduit (e.g., a rushof air that occurs when a door between rooms is opened, equalizing thepressure difference between rooms, or when a window is opened). Suchcoverings also may discourage people from playing with orinappropriately manipulating various parts of the device, which couldlead to damage to the device. For instance, absent the protectivecoverings, a person might be more likely to pull the end stop off of aconduit or inappropriately grasp the conduit as compared to if the endsare surrounding by the protective coverings. Thus, protective coveringsmay provide shielding for components of the device as well as deterpeople from potentially rendering the device non-functional.

To allow observers to view whether the ball is present at a particularend or other region of the conduit, protective coverings may betransparent, or substantially see-through.

FIG. 35 shows an exploded view of the device 100. As shown, theprotective covering 380 fits over the outer wall flange 160 and sealingmaterial 162. The outer wall flange 160 and outer sealing material 162are attached to an inner wall flange 150 via a suitable set offasteners. As discussed previously, the vertical position of a fastenerfor the outer wall flange 160 may be adjustable to suit the desiredangle of incline of the conduit 110. The inner wall flange 150, in turn,is attached to the inner sealing material 152 and the exterior surfaceof the wall (not shown in this figure) via another set of fasteners.

Referring to the conduit 110, the differential pressure set pointindicator 200 is attached to the exterior surface of the conduit. Theball 120 is disposed within the passageway of the conduit and the endsof the conduit are fitted with end stops 130 that prevent the ball fromexiting the conduit while, at the same time, having openings 132 onopposite ends that allow fluid to flow through the length of theconduit. Sound attenuating grommets 140 are placed within respectiveopenings 132 of the end stops so that the ball does not make asubstantially noticeable noise upon impact with the end of the conduit.

Sealing Material

In some embodiments, the sealing material 162 has an opening that has adiameter slightly smaller than the outer diameter of the conduit.Accordingly, the sealing material 162 may form a snug seal with theexterior surface of the conduit, preventing fluid from flowing throughthe opening of the wall flange 160, except through the passageway of theconduit. The diameter of the sealing material 162 is also slightlysmaller than the opening diameter of the wall flange 160 so as toaccommodate various orientations of the angled conduit within theopening of the wall flange 160.

As shown in FIG. 36, when the device is installed, the sealing material162 is in contact with the exterior surface of the conduit so as to forma seal between the surface of the wall (via the wall flanges) and theconduit. The opening of the wall flange 160 may also provide verticaltolerance for the position of the conduit to be adjusted (e.g.,adjusting the angle of inclination of the conduit).

The sealing material may be a gasket that is flexibly deformable. Such acharacteristic allows for the sealing material to accommodateadjustments in position of the conduit, while also maintaining the sealbetween the surface of the wall and the conduit. For example, as shownin FIG. 37, while the conduit may be positioned at a particular angle ofinclination, the seal remains unbroken. Further, the sealing material162 may be composed of a composition that also provides an appropriatedegree of support for the conduit while placed in the angled position.

The sealing material may comprise any suitable composition that isflexible, yet is appropriate for maintaining a seal. In someembodiments, the sealing material includes at least one of an elastomer,rubber, silicone, any other suitable composition and/or combinationsthereof.

While FIG. 37 shows how the sealing material distorts upon adjustment ofthe conduit into an angled orientation, the sealing material 162 notonly maintains the seal so as to prevent fluid flow from one side of thewall to the other over the exterior of the conduit, but also providessupport for the conduit in the angled orientation. That is, the sealingmaterial 162 may function as a gasket that substantially holds theconduit at the angled orientation. Accordingly, the sealing materialmitigates the occurrence of creep of the conduit from its set angledorientation, reducing potential inaccuracies in the overallindication(s) of differential pressure between rooms within whichopposite ends of the conduit are present.

Adjustable Length

In some embodiments, the device includes features that are adjustable inlength so as to accommodate installation of the device into differentwalls of varying thickness.

The embodiment illustrated in FIGS. 38-39 includes the device installedwith telescoping wall cavity barriers 300, 310. Here, the wall flanges150 and associated sealing materials 152 are attached to respective wallcavity barriers 300, 310, which are, in turn, attached to the exteriorsurfaces of the walls 52, 54. As shown in FIG. 38, when installed, thewall cavity barriers 300, 310 define a space within which the conduit110 is housed, providing an additional degree of protection for theconduit within the wall. In some embodiments, wall cavity barriersprovide protection for the conduit from any contaminants within the wallcavity 50 outside the passageway of the wall tubes 304, 305 fromtransmission into either of the rooms 10, 20 or conversely, anycontaminants from either room 10, 20 from entering into the wall cavityoutside the passageway of the wall tubes 304, 305.

As depicted in FIG. 39, the wall cavity barriers 300, 310 may includerespective wall plates 302, 312, wall tubes 304, 314 and sealingmaterials 306, 316. The wall plates 302, 312 provide for attachment ofthe device to the wall during installation. That is, the wall plates maybe attached (e.g., via fasteners, adhesives, etc.) on opposite sides ofthe wall to surfaces 52, 54 so that the wall tubes 304, 314 may extendinto the wall and provide protection and support for the angled conduit.Sealing materials 306, 316 may protect transmission of air between rooms10, 20 and the wall cavity 50.

The wall tubes 304, 314 operatively engage with one another, as shown inFIG. 23, so as to provide a housing for the conduit. For example, thewall tubes may be telescoping or otherwise slidable with respect to oneanother so that the wall cavity barrier may be appropriately installedin walls having different thicknesses. In some embodiments, the walltubes may include features, such as spring-loaded protrusions along thelength of one tube and corresponding holes along the length of anothertube that allow the overall length housed by the wall tubes to befixedly adjustable. Or, the wall tubes may include appropriateinterference/snap fit features that provide length adjustability of thetubes with respect to one another. Alternatively, the wall tubes may beremovably attached to each other via a suitable fastener and/or adhesivematerial. Telescoping tube arrangements may be of a sufficient interfacefit so as to prevent transmission of contaminated or unwanted airbetween the wall cavity 50 and the passageway of the wall tubes 304,314.

As shown in FIGS. 38-39, the sealing materials 306, 316 may haveopenings for respective wall tubes 304, 314 so that a seal is formedbetween the exterior surfaces of the wall 52, 54 and the wall plates302, 312.

In some embodiments, the conduit itself may be adjustable in length.FIGS. 40-41 depict a telescoping conduit. In this embodiment, theconduit includes a first portion 116 and a second portion 118 that areoperatively engaged with one another so as to provide for lengthadjustability of the conduit. For instance, the first and secondportions of the conduit are configured to be telescoping or otherwiseslidable with respect to one another. As a result, the device may beinstalled into different walls having varying thickness.

Similar to the wall tubes discussed above, the first and second portionsof the conduit may include features that allow the length of the conduitto be appropriately adjusted. For example, such portions may includespring-loaded protrusions along the length of one portion andcorresponding holes along the length of the other portion so that theoverall length of the conduit is fixedly adjustable. Or, the conduitportions may have appropriate interference/snap fit features thatprovide length adjustability of the conduit. In some embodiments, therespective portions of the conduit may be removably attached to eachother via a suitable fastener and/or adhesive material.

Fire Stop System

In certain embodiments, the device may include a fire stop system that,upon the detection of a threshold level of smoke or fire, provides abarrier that blocks or otherwise mitigates travel of the smoke/fire fromone room to another. The fire stop system may include various componentsused to seal the passage within the wall. For example, the fire stop mayinclude an intumescent substance that swells significantly as a resultof heat exposure. The fire stop materials may be appropriatelyinstalled, for example, employing intumescent material as known to thoseof ordinary skill in the art. In some cases, the intumescent substancemay produce char, which is a substance that acts to retard heattransfer.

FIG. 42 shows an embodiment where intumescent fire stops 60, 62 areprovided as rings that are located along the wall surfaces 52, 54. Onceexposed to a sufficient level of heat, various parts of the device 100such as the yoke portion 180 and terminal portion 190 may melt orotherwise degrade, and the fire stops 60, 62 will expand radially inwardso as to substantially block the passageway within the wall cavity 50between rooms 10, 20. While FIG. 4 depicts the fire stop system to belocated along the wall surfaces 50, 52 (e.g., formed of anon-combustible material), it can be appreciated that the fire stopsystem may be located at any other suitable location. In someembodiments, a fire stop system may be provided as an intumescent stripor ring located within the passage 198 or sleeve, as shown in FIGS.42-46. Such a configuration may be beneficial where, for certaintemperature ranges, the yoke and/or terminal portions of the device maynot degrade and the intumescent strip or ring more readily expands intothe otherwise open passageway to obstruct travel of smoke or firetherethrough.

In some embodiments, the device may include a gate system installed onone or both sides of the wall which is configured to block thepassageway between rooms upon detection of smoke or fire. FIGS. 42-46depict various embodiments that depict such a gate system, describedfurther below.

FIGS. 42-43 depict an illustrative embodiment of a gate system 800 thatincludes a housing 802 and a shutter 810 provided within the housing,which provides a mechanical guide for the shutter 810 to move betweenopen and closed positions. In various embodiments, the housing 802 mayprovide structure that allows the shutter 810 to slide back and forth(as shown in FIGS. 42-43), swing open and shut (not expressly shown), orhave any other suitable arrangement. The gate system 800 may include abarrier 820 (e.g., fusible link) that keeps the shutter 810 in an openposition, preventing closure thereof until the barrier is broken orotherwise opened. The housing 802 may further include sealing material804 for maintaining a seal between the passage 198 and the surroundingenvironment when the shutter 810 is closed. When the level of smoke orfire reaches a certain threshold, the shutter 810 moves from an openposition to a closed position.

Actuating the gate system 800 in a manner that closes the shutter 810may serve to obstruct air flow within the passageway between rooms,resulting in containment of the smoke and/or fire. Actuation of the gatesystem 800 may involve moving the shutter 810 between open and closedpositions by a suitable stimulus, such as heat, an electrical signaland/or any other appropriate signal. As further shown, an intumescentfire stop material 64 may be located within the passage 198, for formingan occlusion to smoke/fire travel therethrough.

The shutter 810 may be constructed in any suitable manner. For example,the shutter 810 may be weighted such that upon breakage of the barrier820 (e.g., via melting, degradation, etc.), the shutter 810 falls orslides downward (e.g., similar to a guillotine) so as to block theopening into the passageway. Or, as shown for some embodiments, when inthe open position, the shutter 810 is biased toward a closing positionby a spring 812. When the barrier 820 breaks, the spring 812 pulls theshutter from the open position to the closed position. Alternatively, abarrier for holding the shutter to prevent it from closing may not berequired. For example, the shutter 810 may be electromechanicallycontrolled to move back and forth, similar to a sliding gate or garagedoor system. Upon detection of a threshold level of smoke or fire, thegate system may cause the shutter to automatically close, blocking thepassage of smoke/fire between rooms.

The gate system 800 may be mechanically controlled. For instance, asshown in FIGS. 42-43, the barrier 820 for the shutter 810 may be fusiblesuch that, when the barrier 820 is exposed to a sufficient amount ofheat (e.g., temperature up to 165 degrees F. or greater), the barriermay melt or otherwise degrade. Upon degradation of the barrier to asufficient degree, the shutter 810 may be permitted to close, forexample, via weight and/or pulling force caused by the spring 812.

FIG. 42 shows an illustrative embodiment where the passages 178, 188,198 are sufficiently open such that air is able to flow between rooms10, 20, as indicated by the solid arrows. As depicted, the pressuredifference between rooms 10, 20 is large enough that air flowing throughthe conduit 172 causes the ball 120 to be pushed up against the end stop130. Upon exposure to a threshold level of heat (e.g., 150-165 degreesF. or greater), should the ball 120 melt and allow hot fluid/air toreach the barrier, the barrier 820 breaks and the shutter 810 is pulledshut, as depicted in FIG. 43, blocking air flow into the opening 196. Inaddition, FIG. 43 shows the intumescent material of the fire stopmaterial 64 having expanded so as to further block air from travelingthrough the passageway.

In some embodiments, the gate system 800 may be electrically controlled.For example, as shown in FIGS. 44-45, the gate system 800 may be inelectrical communication with a smoke or fire detector/alarm 806. Whenthe smoke or fire detector/alarm 806 senses the presence of a hazardousamount of fire or smoke in either room, a respective signal is sent toan actuator or fusible link 808, allowing for the shutter 810 to movefrom the open position to the closed position. FIG. 44 depicts air flowthrough the passages 198, 188, and 178 causing the ball 120 to be pushedup against the end stop 130. Upon exposure to a threshold level of heatas sensed by the detector 806, the link 808 is caused to break and theshutter 810 is pulled shut by the spring 812, blocking air flow into theopening 196. It can be appreciated that the detector 806 may be locatedat any appropriate location and is not required to be within the wallcavity between spaces. In fact, the detector 806 may be located remotelyexterior to the device (e.g., within one of the rooms). As also providedfor other smoke or fire sensing systems, upon detection of hazardousamounts of fire/smoke, appropriate emergency systems and/or personnelmay also be alerted.

In some embodiments, as shown in FIG. 46, the device 100 may include asleeve 114 forming a secured attachment between other parts of thedevice and the wall. As shown, the sleeve 114 may be located between thewall and the yoke portion 180, and may be mated or coupled therewith.The sleeve 114 may also be attached or otherwise coupled to the housing802 of the gate system 800. The sleeve 114 may also include any suitablematerial, such as metal, non-combustible material, or anotherappropriate material. In some embodiments, the sleeve 114 may beadjustable in length (e.g., telescoping). FIG. 46 further depicts anintumescent strip 66 located within the passage 198, as noted above. Itcan be appreciated that features of this embodiment such as the sleeveand intumescent strip may be suitably employed for any other embodimentin accordance with the present disclosure.

Additional Considerations

Once a room is configured for a particular positive or negative pressuremode, for some cases, the room will typically remain in that positive ornegative pressure mode, despite adjustments in the magnitude of thedesired pressure differential. That is, the net direction of fluid flowbetween spaces may remain the same such that the room remains a positiveor negative pressure room. However, for some applications, it may bedesirable for the pressure mode of a room to be switched betweenpositive and negative pressure.

Accordingly, in various embodiments described herein, to accommodate areversal in the pressure mode between spaces, the overall inclination ofthe conduit may be reversed. That is, the incline of the conduit may beadjusted such that gravity causes the movable element to fall in theother direction. For instance, a straight conduit may be tilted on oneside of the wall from an upwardly inclined to a downwardly inclinedposition, to accommodate for the net directional change in fluid flow.

In an example, animal holding rooms in vivarium research laboratoriesmay have applications that require the room pressure to be switchedbetween positive and negative flow, yet the overall magnitude ofdifferential pressure between spaces remains substantially the same.Accordingly, instead of or in addition to adjusting the incline of theconduit, it may further be convenient for a differential pressureindicator to provide an indication as to whether a particular magnitudeof minimum differential pressure exists between spaces and whether thepressure flow is positive or negative.

The device may include a differential pressure set point indicator thatresponds to the angle of inclination of the conduit with respect to ahorizontal plane. In particular, the differential pressure set pointindicator may be configured and calibrated (e.g., based on a givensize/weight of the movable element, parameters of the conduit, size ofthe openings at each end of the conduit) to correlate the angle ofinclination of the conduit to a threshold differential pressure betweenthe two spaces that is sufficient to cause the movable element withinthe conduit to move from one region (e.g., at a vertically lowerposition) of the conduit toward an opposite region (e.g., at avertically higher position). For example, the greater the degree of tiltof the conduit, the greater the differential pressure required togenerate sufficient fluid flow in the conduit to move the movableelement from a lower region toward a higher region.

In some embodiments, a gravity sensing differential pressure set pointindicator may be calibrated according to the gravitational field of theearth so as to display the directional differential pressure thresholdrequired to move one or more movable elements from a vertically lowerposition of a conduit to a vertically higher position of the conduit.

In some embodiments, an elongated conduit may be adjustable in length.For example, the conduit may have two separate telescoping componentsthat are slidable with respect to one another. Such adjustability inlength may accommodate installation of the device into walls of varyingthicknesses.

The movable element within the conduit may be contained by a stop neareach of the ends of the open ended conduit. When the movable elementimpacts either of the stops of the conduit, in some cases, a noticeablesound may be heard, largely depending on the relative compositions ofthe movable element and the stop(s) of the conduit. For instance, withthe conduit installed at an incline from the horizontal, when thedifferential pressure between spaces becomes equal (e.g., the doorbetween the room and an outside corridor is opened resulting in pressureequalization), the movable element may drop down from a higher verticalposition back to a lower vertical position within the conduit, and theimpact of the movable element with a lower end stop of the conduit mayproduce a sound. Such a sound may be irritating to those in closeproximity to the lower end of the conduit, particularly if repeatedfrequently. For example, hospital inpatients in an infectious isolationroom or laboratory mice in a vivarium, may be awakened during theirsleep cycle each time the staff enters and exits the room. Accordingly,the device may include a sound attenuator that is adapted to reducenoise upon impact of the movable element from one region of the conduitto an opposing region. In some embodiments, the sound attenuator may bea relatively soft energy-absorbing material or include anenergy-absorbing geometry provided as part of an end stop.

The device may further include a sealing material (e.g., gasket) placedin contact with the exterior surface of the conduit so as to provide aseal between the surface of the wall and the conduit when the device isinstalled. Accordingly, transfer of potentially contaminated air betweena space and the interior cavity of a hollow wall may be substantiallyprevented. As the conduit may be positioned at a particular angle ofinclination when installed, the sealing material may be flexible toprovide and maintain a seal as well as accommodate appropriateadjustment(s) in position of the conduit (e.g., from one angle ofincline to another). Yet, for some embodiments, the sealing material mayalso be firm enough to provide a suitable amount of support for thetilted conduit (e.g., to maintain the position/orientation of theconduit).

In an illustrative embodiment, a device for indicating directionaldifferential pressure between two spaces is provided. The device mayinclude an elongated conduit arranged to be coupled with andsubstantially located on one side of a wall separating a first spacefrom a second space. The conduit may have openings that permit fluidflow through the conduit from the first space toward the second space.The conduit may be arranged to be adjustably inclined with respect to ahorizontal reference plane such that a first region of the conduitassociated with the first space is vertically lower than a second,vertically higher region of the conduit that is associated with thesecond space. The device may include at least one movable elementdisposed within the conduit adapted to be moved from the first,vertically lower region of the conduit to the second, higher region orfrom the second higher region to the first vertically lower region, inresponse to a differential pressure between the first and second spaces.The device may include a differential pressure set point indicatorconfigured to correlate each of a plurality of angles of inclination ofthe conduit with respect to the horizontal reference plane to arespective threshold differential pressure between the first and secondspaces that is sufficient to cause the at least one movable element tomove from the first, lower region of the conduit to the second, higherregion.

In another illustrative embodiment, a device for indicating adirectional differential pressure between two spaces is provided. Thedevice may include an elongated conduit arranged to be coupled with awall separating a first space from a second space, the conduit havingopenings that permit fluid flow through the conduit from the first spacetoward the second space, the conduit arranged to be inclined withrespect to a horizontal or vertical reference plane such that a firstregion of the conduit associated with the first space is verticallylower than a second, vertically higher region of the conduit that isassociated with the second space. The device may include at least onemovable element disposed within the conduit adapted to be moved from thefirst, vertically lower region of the conduit to the second, higherregion or from the second higher region to the first vertically lowerregion, in response to a differential pressure between the first andsecond spaces. The device may further include a differential pressureset point indicator configured to correlate each of a plurality ofangles of inclination of the conduit with respect to the horizontal orvertical reference plane to a respective threshold differential pressurebetween the first and second spaces that is sufficient to cause the atleast one movable element to move from the first, lower region of theconduit to the second, higher region.

In another illustrative embodiment, a device for indicating adirectional differential pressure between two rooms is provided. Thedevice may include an elongated conduit arranged to be coupled with awall separating the two spaces, the conduit having openings ends thatpermit fluid flow between the two spaces through the conduit, theconduit being adjustable in length, and at least one movable elementdisposed within the conduit adapted to be moved from one region of theconduit toward an opposing region in response to the differentialpressure.

In yet another illustrative embodiment, a device for indicating adirectional differential pressure between two rooms is provided. Thedevice may include an elongated conduit arranged to be coupled with awall separating the two spaces, the conduit having openings that permitfluid flow between the two spaces through the conduit; at least onemovable element disposed within the conduit adapted to be moved from oneregion of the conduit toward an opposing region in response to thedifferential pressure, and a sound attenuator adapted to reduce noiseupon the movable element reaching one of the two conduit ends.

In another illustrative embodiment, a device for indicating adirectional differential pressure between two rooms is provided. Thedevice may include an elongated conduit arranged to be coupled with awall separating the two spaces, the conduit having openings that permitfluid flow between the two spaces through the conduit; a sealingmaterial in contact with an exterior surface of the conduit and adaptedto support the conduit in an installed orientation, and at least onemovable element disposed within the conduit adapted to be moved from oneregion of the conduit toward an opposing region in response to thedifferential pressure.

In an illustrative embodiment, a device for indicating directionaldifferential pressure between two spaces is provided. The device mayinclude an elongated conduit arranged to extend through a wallseparating a first space from a second space, the conduit havingopenings that permit fluid flow through the conduit from the first spaceto the second space, the conduit arranged to be inclined with respect toa horizontal reference plane such that a first region of the conduitassociated with the first space is vertically lower than a second,vertically higher region of the conduit that is associated with thesecond space. The device may include a plurality of movable elementseach adapted to provide a set point indication of a respective thresholddifferential pressure between the first and second spaces that issufficient to cause the movable element, when disposed within theconduit, to move from the first, vertically lower region of the conduitto the second, vertically higher region in response to a differentialpressure between the first and second spaces.

In another illustrative embodiment, a device for indicating directionaldifferential pressure between two spaces is provided. The device mayinclude an elongated conduit arranged to extend through a wallseparating a first space from a second space, the conduit havingopenings that permit fluid flow through the conduit from the first spaceto the second space, the conduit arranged to be inclined with respect toa horizontal reference plane such that a first region of the conduitassociated with the first space is vertically lower than a second,vertically higher region of the conduit that is associated with thesecond space. The device may include a movable element disposed withinthe conduit, wherein the conduit is adapted to provide a set pointindication of a respective threshold differential pressure between thefirst and second spaces that is sufficient to cause the movable elementto move from the first, vertically lower region of the conduit to thesecond, vertically higher region in response to a differential pressurebetween the first and second spaces.

In an illustrative embodiment, a device for indicating directionaldifferential pressure between two spaces is provided. The device mayinclude a conduit arranged to be coupled with and substantially locatedon one side of a wall, the wall separating a first space and a secondspace, the conduit having openings that permit fluid flow through theconduit as part of allowing flow between the first space and the secondspace, wherein an angle of inclination of the conduit is adjustable withrespect to a horizontal reference plane such that a first region of theconduit is vertically lower than a second, vertically higher region ofthe conduit. The device may further include at least one movable elementdisposed within the conduit and adapted to move from the first,vertically lower region of the conduit to the second, higher region, inresponse to a differential pressure between the first and second spaces.The device may include a differential pressure set point indicatorconfigured to correlate each of a plurality of angles of inclination ofthe conduit with respect to the horizontal reference plane to arespective threshold differential pressure between the first and secondspaces that is sufficient to cause the at least one movable element tomove from the first, lower region of the conduit to the second, higherregion.

In another illustrative embodiment, a device for indicating directionaldifferential pressure between two spaces is provided. The device mayinclude a first conduit arranged to extend through a portion of a wall,the wall separating a first space from a second space. The first conduitmay have openings that permit fluid flow through the first conduitbetween the first space and the second space. The device may include ayoke body adapted to be coupled to one side of the wall and to house anend of the first conduit that extends through the portion of the wall.The device may include a second conduit rotatably (e.g., pivotally)coupled to the yoke body and in fluid communication with the firstconduit. The second conduit may have openings that permit fluid flowthrough the second conduit between the first space and the second space.The second conduit may be arranged to be adjustably inclined withrespect to a horizontal or vertical reference plane such that a firstregion of the second conduit associated with the first space isvertically lower than a second, vertically higher region of the secondconduit associated with the second space. The device may include atleast one movable element disposed within the second conduit adapted tobe moved from the first, vertically lower region of the second conduitto the second, vertically higher region, in response to a differentialpressure between the first and second spaces. The device may include adifferential pressure set point indicator to correlate each of aplurality of angles of inclination of the second conduit with respect tothe horizontal or vertical reference plane to a respective thresholddifferential pressure between the first and second spaces that issufficient to cause the at least one movable element to move from thefirst, vertically lower region of the conduit to the second, verticallyhigher region.

In yet another illustrative embodiment, a method of installing a devicefor indicating a differential pressure between two spaces is provided.The method may include positioning an elongated conduit on one side of awall separating a first space from a second space, the conduit havingopenings that permit fluid flow through the conduit from the first spaceto the second space, the conduit arranged to be inclined with respect toa horizontal reference plane such that a first region of the conduitassociated with the first space is vertically lower than a second,vertically higher region of the conduit that is associated with thesecond space, wherein at least one movable element disposed within theconduit is adapted to be moved from the first, vertically lower regionof the conduit to the second, higher region in response to adifferential pressure between the first and second spaces. The methodmay include referring to a differential pressure set point indicator todetermine a first angle of inclination of the conduit with respect to ahorizontal reference plane that corresponds to a first thresholddifferential pressure between the first and second spaces that issufficient to cause the at least one movable element to move from thefirst, lower region of the conduit to the second, higher region. Themethod may include tilting the conduit to achieve the determined firstangle of inclination of the conduit with respect to the horizontalreference plane that corresponds to the first threshold differentialpressure. The method may include referring to the differential pressureset point indicator to determine a second angle of inclination of theconduit with respect to the horizontal reference plane that correspondsto a second threshold differential pressure between the first and secondspaces, different from the first threshold differential pressure, thatis sufficient to cause the movable element to move from the first, lowerregion of the conduit to the second, higher region. The method mayinclude tilting the conduit to achieve the determined second angle ofinclination of the conduit with respect to the horizontal referenceplane that corresponds to the second threshold differential pressure.

In another illustrative embodiment, a device for indicating directionaldifferential pressure between two spaces is provided. The device mayinclude at least one conduit arranged to extend through a wallseparating a first space from a second space, the at least one conduithaving openings that permit fluid flow through the at least one conduitbetween the first space and the second space, the at least one conduithaving a first portion, a second portion and a middle portion, the firstportion extending from the first space toward the middle portion andinclined with respect to a horizontal reference plane such that an endof the first portion located within the first space is vertically higherthan the middle portion, the second portion extending from the secondspace toward the middle portion and inclined with respect to thehorizontal reference plane such that an end of the second portionlocated within the second space is vertically higher than the middleportion. The device may further include at least one movable elementdisposed within the at least one conduit and movable from the firstportion of the at least one conduit to the second portion of the atleast one conduit in response to a differential pressure between thefirst and second spaces.

In some embodiments, the conduit includes a conductive material adaptedto dissipate electrostatic charge build-up that may otherwise arisetherein.

In some embodiments, the air flow traveling through the conduit from oneroom to an adjacent room may be stopped, reversed or otherwise regulatedas desired, by any suitable method regardless of the angle of theapparatus' vertically-adjustable conduit.

Having thus described several aspects of at least one embodiment of thepresent disclosure, it is to be appreciated various alterations,modifications, and improvements will readily occur to those skilled inthe art. Such alterations, modification, and improvements are intendedto be part of this disclosure, and are intended to be within the spiritand scope of the present disclosure. Accordingly, the foregoingdescription and drawings are by way of example only.

What is claimed is:
 1. A device for indicating a presence of adirectional differential pressure between a first space and a secondspace separated from the first space by a barrier, the device permittingfluidic pressure connection between the second space and the firstspace, the device comprising: an inclined conduit configured to form afluidic pressure connection between the first space and the secondspace, wherein the inclined conduit includes a first region and a secondregion, and wherein the first region is vertically lower than the secondregion, wherein the inclined conduit is rotatably attached to thebarrier to permit adjustment of an inclination of the inclined conduitrelative to a horizontal plane, and wherein the inclined conduit isrotatable about an axis of rotation which is transverse to the barrier,and the inclined conduit is rotatable along a plane; at least onemovable element disposed within the inclined conduit and movable fromthe first region of the inclined conduit to the second region of theinclined conduit in response to a differential pressure between thefirst space and the second space; a base configured to be coupled to thebarrier; and a pitch level disposed on the base, wherein the pitch levelis configured to indicate whether the device is oriented correctly withrespect to pitch.
 2. The device of claim 1, wherein the pitch level isconfigured to verify that the axis of rotation of the inclined conduitis horizontal.
 3. The device of claim 1, wherein the pitch levelresponds to gravity.
 4. The device of claim 1, further comprising adifferential set point indicator configured to correlate at least oneangle of inclination of the inclined conduit to a respective thresholddifferential pressure between the first space and the second space thatis sufficient to cause the at least one movable element to move from thefirst region of the inclined conduit to the second region of theinclined conduit.
 5. The device of claim 4, wherein the differential setpoint indicator comprises at least one stationary mark on the device andat least one movable mark that moves when the inclined conduit isrotated, and wherein the device further comprises a roll indicator thatresponds to gravity.
 6. The device of claim 4, wherein the differentialset point indicator comprises a bubble vial.
 7. The device of claim 6,wherein the bubble vial is mounted on a sloped baseplate which ismounted to the inclined conduit.
 8. The device of claim 4, wherein thedifferential set point indicator comprises a weighted pointer thatresponds to gravity.
 9. The device of claim 8, wherein the differentialset point indicator is configured to travel in a plane that isperpendicular to the axis of rotation of the inclined conduit.
 10. Thedevice of claim 9, wherein the differential set point indicator isconfigured to travel in a vertical plane.
 11. The device of claim 1,further comprising an additional conduit configured to extend through atleast a portion of the barrier separating the first space and the secondspace, wherein the inclined conduit is in fluid communication with theadditional conduit.
 12. The device of claim 1, wherein the axis ofrotation of the inclined conduit is perpendicular to the barrier. 13.The device of claim 1, where the at least one movable element is aplurality of movable elements, each movable element of the plurality ofmovable elements having a different weight from others of the pluralityof movable elements, and each movable element of the plurality ofmovable elements being configured to be placed in the inclined conduit,and each of the plurality of movable elements corresponding to adifferent threshold differential pressure set point, the thresholddifferential pressure set point representing a differential pressurebetween the first space and the second space that is sufficient to causethe respective movable element disposed within the inclined conduit tomove from the first region of the inclined conduit to the second region.14. The device of claim 1, wherein the at least one movable elementcomprises a first ball having a first diameter, and the device furthercomprises a second ball having a second diameter which is different fromthe first ball, such that, as compared to using the first ball, usingthe second ball requires a different threshold differential pressurebetween the first space and the second space to be sufficient to causethe second ball to move from the first region of the inclined conduit tothe second region of the inclined conduit.